Abstract
Governments across Europe increasingly limit fundamental rights to defend themselves against internal threats. Distinguishing between procedural and substantive notions of liberal-democratic self-defense, we evaluate the adoption and removal of legal provisions formally designed to address serious harm to the state, to the democratic process, and to liberal values in the regulation of freedom of association, assembly, and expression across 12 European democracies from 2000 to 2022. We find significant legal change: today’s governments can curtail fundamental rights not only to ensure democratic survival and citizens’ equal political rights, but also to promote liberal values within society at large. Relatedly, they can counter the expression of ‘wrong ideas’ or ‘beliefs’ without individuals and groups engaging in harmful behavior. Taken together, these two developments point to a shift in the nature of self-defense embodied by these systems’ legal architectures, which increasingly align with a broader substantive notion of self-defense. This is important for democracy. Although often legally designed to enhance liberal orders’ resilience, as illiberal leaders and parties take office, pre-existing as well as newly adopted rights limitations increasingly risk being used to silence legitimate voices.
Introduction
Recently, there has been a growing interest in civil society regulation, 1 especially the regulation of the fundamental rights of freedom of expression, association, and assembly – critical for maintaining a politically active and democratic civil society – and, relatedly, democratic resilience 2 (e.g. Bloodgood et al., 2014; Bolleyer, 2018; Buyse, 2018; Chaudhry, 2022; Chaudhry and Heiss, 2022; Glasius et al., 2020; Merkel and Lührmann, 2021; Swiney, 2022). 3 Research on the regulation of fundamental rights, as well as on legal reform responding to terrorism or extremism, has long indicated that democracies increasingly condition (i.e. limit) the exercise of fundamental rights to prevent their abuse and to enable democracies to counter serious harm to the liberal-democratic order (e.g. Ashworth and Zedner, 2014; Bleich, 2011; Cram, 2016; Eckes, 2009; Salát, 2015; Zeller and Vaughan, 2023). Despite rising concerns about these developments – as elected governments in Europe not just overstep their powers but abandon their political order’s core principles – there is still a lack of systematic, cross-national analyses of the variety of limitations in the critical domains of freedom of expression, association, and assembly within liberal-democratic states’ legal frameworks. Newly adopted provisions are usually framed as ‘countermeasures’ against the abuse of rights by ‘harmful’ actors. Yet, as cross-national analyses of the evolution and range of legal limitations on the rights of political participation and expression remain scarce (Capoccia, 2019: 134), it is unclear which types of harm these limitations actually address across fundamental rights domains and to what extent governments are creating an ever-broader repertoire of coercive means to counter them. 4
This article therefore addresses the following closely interconnected questions: To what extent have democracies in Europe experienced a ‘restructuring of fundamental rights’ in the post-9/11 period, as has been prominently argued (Sajó, 2006: 2265), in the sense that they have increasingly adopted limitations on fundamental rights formally designed to counter serious harm to the liberal-democratic state? Which types of harm do these measures, justified by reference to liberal-democratic self-defense, increasingly address, and what were the major drivers behind these developments?
To comprehensively trace the evolution of rights limitations embedded in the domains of freedom of expression, association, and assembly, this article builds on Loewenstein’s seminal work. He mapped out a particularly broad repertoire of rights limitations that democratic states might have at their disposal to protect the liberal-democratic order (Loewenstein, 1937a: 418–419, 1937b: 648–653). Accordingly, self-defense measures can be designed to address three types of harm: harm to the state, to the democratic process, and to liberal values. These categories provide analytical tools for empirically specifying the repertoires of rights limitations that form a part of democracies’ legal architectures.
Having generated comprehensive legal data on the evolution of rights limitations, we evaluate the nature of changes in states’ rights infrastructures based on the distinction between procedural and substantive democracy (e.g. Bourne, 2012, 2022; Fox and Nolte, 1995; Malkopoulou and Kirshner, 2019; Stahl and Popp-Madsen, 2022). Under a procedural notion of self-defense, linked to the former, the state’s role in ‘managing’ societal pluralism is narrowly defined. The state acts as a neutral arbiter or gatekeeper, intervening in rights ‘solely’ to ensure equal liberty among citizens in the political realm and the basic preconditions thereof (Fox and Nolte, 1995: 14–16). In other words, it counters harm to the democratic process and to the state itself. By contrast, the substantive notion of self-defense – aligning with substantive democracy and Loewenstein’s (1937a, 1937b) broader understanding of self-defense – views the state as a proactive guardian of democratic and liberal values within the political and societal realms. This implies that a wider range of rights limitations can be justified in the name of self-defense. Accordingly, the adoption of a provision criminalizing speech that degrades certain groups – a limitation that addresses harm to liberal values rather than to the democratic process or state functioning – signals an endorsement of the substantive notion of self-defense. Such a provision does not align with the narrower procedural notion, which requires state neutrality and opposes the promotion of liberal values. If then European democracies were to increasingly adopt such rights limitations, the notion of self-defense embedded in their legal architectures would become more ‘expansive’ (and increasingly contradict the more restrained procedural notion). This would allow governments to justifiably curtail fundamental rights in a growing range of scenarios. 5
Our empirical analysis maps and evaluates the rights limitations designed to address harm to the liberal-democratic order adopted, modified, or removed from the domains of freedom of expression, association, and assembly across 12 European democracies between 2000 and 2022. Although legal pluralism and entrenched state traditions represented by our country cases play an important role in shaping the normative and institutional dimensions of legal systems in the region, we show that common contemporary internal and external challenges faced by these states, as well as processes of internationalization, prompted shared or convergent responses that defy rigid a priori classifications on the polity level.
Indeed, our findings suggest that repertoires of rights limitations to counter harm to the liberal-democratic state have considerably broadened over the past two decades. Today’s state authorities can place limits on the exercise of freedom of expression, association, and assembly by their citizens not just to protect the democratic process, the central concern of more recent militant democracy research (e.g. Capoccia, 2013; Kirshner, 2014; Müller, 2018, 2019; Vinx, 2020). Increasingly endorsing a substantive notion of self-defense through legal reform, a growing number of states limit rights to ensure compliance with liberal values more broadly. They go beyond protecting the democratic process and the equal rights of individuals qua citizens, and increasingly employ rights limitations to counter harm to liberal values, that is, to human dignity in all spheres of life. Governments can also increasingly respond to citizens’ expression and promotion of ‘wrongful’ ideas in a coercive fashion without citizens actually engaging in harmful behavior. Normatively, these findings raise concerns about liberalism turning into a positive doctrine that tells people how to live their lives, risking violating its own constitutive principles, such as state neutrality, equality, and tolerance (e.g. Adamson et al., 2011; Enyedi, 2024; Kis, 2012; Mouritsen and Olsen, 2013). Empirically, as parties with illiberal agendas come to power, most strikingly illustrated by Hungary, questions arise around how specific governments implement such provisions and to what extent their adoption could be seen as part of a broader autocratization process. These are fundamental questions concerning democratic resilience and erosion, themes to which we will return in the conclusion.
In the following, we develop our analytical framework to empirically study the changing nature of self-defense measures in European democracies. Having introduced our methodology and data, we present the findings and conclude with a discussion of our findings’ broader repercussions.
The expanding scope of rights limitations in liberal-democratic states: Beyond the protection of democracy
Rights limitations are binding formal-legal provisions that form part of a democracy’s normal legal architecture 6 and impose costs on, curtail, or condition citizens’ exercise of fundamental rights, such as freedom of expression, assembly, and association. Since Loewenstein (1937a, 1937b), research on democratic militancy or self-defense has studied how democracies can counter serious harms to the liberal-democratic order, typically considering limitations on the rights of violent, anti-democratic, or anti-system actors as an essential means of protecting liberal democracy from within. Rights limitations designed as ‘countermeasures’ impose formal constraints on actors or activities deemed harmful in order to protect liberal democracy’s constitutive characteristics, thereby seeking to enhance democratic resilience (Merkel and Lührmann, 2021). Criminalizing violence-inciting speech to counteract the intimidation of minorities – ensuring they are able to freely exercise their equal political rights – is one example of the legal provisions we are concerned with: rights limitations explicitly designed to address different types of serious harm to the liberal-democratic order, which thereby can be attributed a ‘protective purpose’ (e.g. Bleich, 2011; Cram, 2016; Salát, 2015; Zeller and Vaughan, 2023).
To develop conceptual tools to capture and empirically analyze the evolution of such rights limitations across liberal democracies, we start out from Ashworth and Zedner’s (2014) seminal work on the ‘preventive state’. They have stressed that – irrespective of the level of problem exposure – in a liberal-democratic order ‘the authorized deprivation of basic rights’ needs to be justified and such justification tends to rest ‘in the harm that the coercion is designed to avert or minimize’ (Ashworth and Zedner, 2014: 7–8; Sajó, 2006). Consequently, they put center-stage the question of which types and manifestations of harm merit to be addressed through – and hence can justify – the formal-legal curtailing of fundamental rights within a liberal-democratic framework.
Empirically, this question has gained salience as liberal democracies have started to face new domestic challenges, including terrorism, extremism, and rising illiberalism (Bourne and Casal Bértoa, 2017: 222; Merkel and Lührmann, 2021). Meanwhile, political theorists continue to discuss whether and how to ‘expand the scope of application of militant democracy’ or ‘liberal-democratic self-defense’ (Malkopoulou and Moffit, 2023: 855), a concept that tended to be used for measures to prevent the takeover of anti-democratic actors and successive undermining of democracy from within (Bourne, 2022: 491; see, for different theoretical perspectives, Malkopoulou and Kirshner, 2019; Müller, 2018, 2019; Schupmann, 2024; Stahl and Popp-Madsen, 2022; Vinx, 2020). Interestingly, going back to Loewenstein (1937b) and his empirical assessment of self-defense measures in European states in the 1930s, he refers to a much wider range of provisions than those designed to prevent ‘democratic suicide’, the takeover of anti-democratic actors and erosion of democracy from within. Aligning with Ashworth and Zedner’s (2014) perspective on the preventive state, which is influenced by liberal states’ exposure to a diversity of threats, the measures Loewenstein (1937b) detects range from limitations on organizations deemed inimical to the state or threatening public order, to provisions preventing the subversion of the democratic process and restrictions on degrading speech toward minorities (pp. 648–653). Developed in a period in which European politics was under enormous strain, his empirically oriented perspective can usefully inform an encompassing mapping of rights limitations addressing serious harm that liberal-democratic states might have adopted over the past decades.
Consequently, to capture a wide repertoire of rights limitations designed as protective countermeasures that might form part of European states’ legal architectures, we define ‘liberal-democratic self-defense’ in terms of three types of serious harm to the ‘liberal-democratic state’ – rather than merely to ‘democracy’ or ‘liberal democracy’. Each corresponds to one of the pillars that is constitutive to the identity of this type of order, that is, critical to its resilience (Merkel and Lührmann, 2021): harm to the state and its basic functions/functioning; harm to the constitutive features of the democratic process; and harm to liberal values. 7
Harm to the state refers to threats that endanger the foundations and stability of the state apparatus and is therefore a concern for any political regime, democratic or not (Pfersmann, 2004: 57; Sajó, 2004: 213). This category of harm refers to threats to public order or basic entitlements, such as protection from violence. As rights limitations countering such harm are not exclusively justifiable by reference to liberal-democratic principles, they are often left aside by militant democracy scholars focused on normative repercussions (e.g. Müller, 2016). Being interested in how liberal orders might try to ensure their resilience through actual self-defense measures instead, a functioning state constitutes a necessary precondition for implementing constitutive rights guarantees and providing the institutional infrastructure for citizens to meaningfully exercise them (Ashworth and Zedner, 2014; Bolleyer et al., 2026b; Holmes and Sunstein, 2000; Loewenstein, 1937b: 645; Thiel, 2009: 1).
Harm to the democratic process concerns threats to democracy, its institutions, and central actors, including the basic preconditions for protecting the equal rights of citizens as political participants and for maintaining government accountability to the citizenry (Fishman, 2025: 99–100). This type of harm reflects the traditional focus of militant democracy research, concerned with safeguarding democratic survival. For instance, it includes totalitarian speech and actions that deny certain groups political participation, thus risking the erosion of equal citizen participation at the heart of the democratic process (Bourne, 2022: 491; Capoccia, 2019; Müller, 2016).
Finally, harm to liberal values goes beyond protecting the democratic process and the equal rights of individuals qua citizens, addressing threats to human dignity in all spheres of life. Following Glasius (2018: 517), we distinguish between authoritarian practices – undermining accountability structures in the political domain, aligning with our notion of harm to the democratic process – and illiberal practices, which violate norms of individual autonomy and dignity, corresponding to harm to liberal values (Glasius, 2018: 530–531). Applied to citizens’ behavior (instead of state actors), this framework helps identify when the exercise of rights may constitute abuse and thus justify governmental restrictions. It also parallels Merkel and Lührmann’s (2021: 869–870) distinction of illiberal (as compared with authoritarian) challenges by actors in a political order not fully committed to its liberal dimensions, such as civil liberties. Examples of countermeasures justifiable only by reference to this third type include prohibitions on speech degrading minorities, bans on racist organizations, and restrictions on discriminatory displays in public assemblies. These measures address broader human rights problems at the societal level, which do not necessarily concern the political, democratic process as strictly understood (Glasius, 2018: 517). 8 Such limitations may be framed – depending on a democracy’s self-understanding – as a way of defending foundational values of liberal constitutionalism, reflecting a broader notion of self-defense (Schupmann, 2024: 56–59).
This extensive understanding of self-defense – justifiable by reference to harms beyond immediate threats to the democratic process – is not without its critics. Concerned about the risks of granting governments wide-ranging powers to curtail citizens’ fundamental rights, various theorists have criticized Loewenstein’s understanding of self-defense as intrusive, with some even considering him a proponent of ‘authoritarian liberalism’ violating fundamental norms that the liberal state ought to uphold (Invernizzi-Accetti and Zuckermann, 2019: 73–74; see, for overviews, Müller, 2016; Stahl and Popp-Madsen, 2022). Essentially, while the liberal state ‘fixes the boundary conditions and basic rules of all associational activity’ (Walzer, 1992: 302), the types of rights limitations one considers justifiable depends on the normative understanding of liberal democracy endorsed. These understandings are critical as they suggest different grounds for, and limits on, public authorities’ power to try to protect the constitutive characteristics of liberal-democratic orders through regulating fundamental rights (Billingham, 2019; Cram, 2016; Kymlicka, 2002).
Two modes of justifying rights limitations as self-defense: Building on the distinction between procedural and substantive democracy
To qualify concrete rights limitations designed to counter harms to the liberal-democratic order as normatively (un)justifiable self-defense measures, we employ the dichotomy between a procedural and substantive notion of democracy. A number of legal and comparative politics scholars have made this distinction useful in empirical analyses, mainly trying to account for countries’ different inclinations to adopt, employ, or tolerate repressive legal means, such as party bans, against societal actors threatening the liberal-democratic order from within (e.g. Backes, 2006; Beimenbetov, 2014; Bourne and Casal Bértoa, 2017; Capoccia, 2013; De Leeuwe and Bourne, 2020; Fox and Nolte, 1995). Building on these authors, we use the procedural-substantive dichotomy to distinguish two notions of self-defense, suggesting different ranges of rights limitations that can be justified as self-defense.
The procedural notion, associated with value pluralism, tolerance, and a thin understanding of democracy as an institutional modus operandi, characterizes the state’s role in society as that of a neutral arbiter or gatekeeper, tasked ‘solely’ with ensuring equal liberty among citizens in the political realm (Fox and Nolte, 1995: 14–16). Within this notion, ‘democracy must open the same possibilities of action to all, including anti-democratic political forces’, which prevents the state from promoting particular values, including liberal ones (Backes, 2006: 270). The procedural notion therefore presupposes tolerance toward the coexistence of diverse viewpoints (Bourne, 2022: 492). Thus, the role of the state is limited to ensuring that these viewpoints can be freely expressed – that is, that rights can be meaningfully exercised – including by controversial or marginalized groups. While this justifies some rights limitations, the types and manifestations of harm that warrant such limitations under the procedural notion remain narrowly defined (Vinx, 2020: 689). Specifically, the state can only curtail rights when their exercise by some citizens has concrete negative consequences for others as political participants and thereby undermines their ability to enjoy the same rights (Vinx, 2020: 690–692). This also applies where such behavior threatens the basic preconditions for the democratic process, for instance by inciting violence against certain groups (Sajó, 2019: 194). Under the procedural notion, authorities therefore refrain from regulating the mere expression of beliefs or ideas in society, even where these are considered ‘harmful’ or ‘incongruent’ – as political theorists describe them – with the state’s normative foundations, as with illiberal, extremist, or anti-democratic viewpoints (Chambers and Kopstein, 2008: 365–367; Rosenblum, 1994: 551–553). This principle of non-interference with societal pluralism implies that, under the procedural notion, only the regulation of concrete harmful behavior threatening the democratic process is deemed justifiable. This has implications, discussed below, for the types of harm that can justify rights limitations that, in turn, qualify as self-defense measures.
By contrast, the substantive notion of democracy – aligning with Loewenstein’s (1937a, 1937b) broad notion of militancy – considers the state as an active guardian of democratic and liberal values, authorized to proactively limit citizens’ exercise of fundamental rights to protect the normative underpinnings of the liberal-democratic state. Democracy is seen as being about more than just institutional procedures; it is ‘a society in which majority rule is made meaningful’ (Fox and Nolte, 1995: 16). This justifies a broader engagement of the state in creating a society that, though plural, still respects its core values, such as equal liberty and pluralism (Bourne, 2012: 7; Nussbaum, 2011; Rosenblum, 1994). Reflecting a ‘thick or substantive constitutional identity’ (Vinx, 2020: 686), the types and manifestations of harm justifying rights limitations, and thus the repertoire of self-defense, are considerably broader. Following this substantive notion, the reach of justifiable rights limitations extends beyond countering concrete behavioral harm to include manifestations of ‘harmful’ beliefs and ideas. Furthermore, as discussed below, it covers not only the state and democratic process, but also those liberal values that, on this view, constitute the shared normative foundation of liberal-democratic states.
Table 1 summarizes the central conditions that rights limitations, that is, actual legal provisions, ought to meet under a procedural as compared with a substantive notion of self-defense to qualify as justifiable self-defense measures or countermeasures, constituting an analytical map to analyze the nature of rights limitations empirically. The first condition concerns the manifestation of harm that a legal provision analyzed is designed to counter. It asks whether a concrete rights limitation regulates the expression of ‘harmful’ beliefs and ideas, or even intentions toward harmful behavior, in society – only justifiable under a substantive notion of self-defense – or whether it is restricted to regulating concrete harmful behavior that occurs within the political sphere – as required under a procedural view. The second condition concerns the types of harm the state can justifiably counter through rights limitations: harm to the state, to the democratic process, or to liberal values.
Rights limitations addressing serious harm that qualify as self-defense under procedural and substantive notions.
The dark gray cells indicate that, from the procedural perspective, limits on fundamental rights are permissible only in circumstances that impact concretely and negatively the unfolding of the democratic political process, understood narrowly as a ‘framework for decision-making’ (Fox and Nolte, 1995: 14). Since they aim to safeguard the ongoing democratic procedure through which shifting majorities are formed over time (Fox & Nolte, 1995: 15), limitations designed to counter concrete harm to democracy are justifiable as self-defense. As an enabling state infrastructure that guarantees security and formal rights to all is essential, rights limitations countering concrete harm to the state are also necessary (Holmes and Sunstein, 2000; Pfersmann, 2004: 63; Rosenblum, 2008: 423; Sajó, 2004: 213; Thiel, 2009: 2–3). 9 By contrast, limiting rights to protect liberal values in society is unjustified, as it interferes with pluralism without directly safeguarding democratic mechanisms. Concretely, in the domains of freedom of association, assembly, and expression, this means that under a procedural conception, it would be permissible to ban groups engaged in terrorism or direct violations of democratic norms, to restrict violence-inciting speech, and to disperse assemblies that violate the rights of others or threaten public safety. By contrast, prohibiting speech or groups solely for expressing anti-democratic or discriminatory ideas would not be justifiable, as these measures would suppress the circulation of ideas in society rather than prevent concrete negative consequences for democracy and its participants.
The substantive conception of self-defense gives the state – a guardian of liberal values – considerably more leeway to interfere with rights. As shown in the light gray cells, in addition to countering concrete harms to the state and the democratic process, it allows for governments to limit the expression of beliefs and ideas, and covers harm to liberal values. Both ‘expansions’ of the notion of harm justifying rights limitations are rooted in strong concerns about threats to the liberal-democratic state from uncivil, illiberal, undemocratic, or extremist parts of society, seen as harmful under a substantive understanding of democracy for not sharing those core values that underpin liberal-democratic orders (e.g. Rosenblum, 2008: 433; Stahl and Popp-Madsen, 2022). Taking these two conditions together, societal threats might require curtailing the mobilization of harmful belief before relevant actors can enter institutional positions of power, and before publicly expressed beliefs can translate into harmful behavior, a point in time when ‘militant’ countermeasures against them can no longer be employed or might no longer be effective (Capoccia, 2013: 213–214; Loewenstein, 1937a; Müller, 2019).
Concretely, while endorsing the same protective rights limitations as the procedural conception, a substantive notion of self-defense allows for a much broader remit of protective countermeasures in the three rights domains. These include group bans targeting the expressed intent, glorification, or support of ideas that are hostile to democracy, anti-state, or otherwise in conflict with the liberal constitutional order. Freedom-of-expression limitations can extend beyond curtailing speech that actively incites harm (e.g. to the state, public order, or democracy) to include countering disinformation, glorification of anti-state ideas, or praise of totalitarianism. Finally, it justifies prohibiting symbols and chants inciting discrimination in assemblies, speeches propagating non-liberal ideologies (including non-political ones such as religious fundamentalism), and the denial or trivialization of the Holocaust and other historical atrocities.
Country selection
We analyzed the evolution of fundamental rights limitations in Austria, Germany, Spain, France, Greece, Hungary, Ireland, Italy, Latvia, Malta, Poland, and the United Kingdom between 2000 and 2022. 10 EU countries’ governments – ceteris paribus – face high expectations from their populations as well as political pressures from fellow member states to protect their citizens’ fundamental rights, counter rights abuse, and defend democracy. Relatedly, all countries in our study are democracies throughout, except for Hungary, which was downgraded to an ‘electoral autocracy’ in 2019, a development we return to in our analysis. 11 Simultaneously, our 12 countries differ in terms of legal and political traditions, suggesting variation in the degree to which state authorities interfere in fundamental rights (Bolleyer, 2018; Klamt, 2007; Moroska-Bonkiewicz and Bourne, 2020). They also have been exposed to crises or internal threats to very different extents, inviting different legal manifestations of self-defense (Thiel, 2009: 6; Sajó, 2006). These include exposure to domestic terrorism and government parties with illiberal agendas (e.g. Ashworth and Zedner, 2014; Bolleyer, 2022; Swiney, 2022). While these systemic and political cross-country differences are important to rationalize distinct country clusters in the evolution of self-defense measures, 12 if we nevertheless find an overall trend toward a more expansive, substantive notion of self-defense, this is likely to signify a pervasive alteration of the normative foundations of liberal-democratic states across Europe.
Data
We assessed national legislation in terms of the presence/absence of legal provisions limiting rights to address serious harms to the liberal-democratic order, that is, self-defense measures broadly defined, following earlier comparative analyses of legal change that coded original legislation across different legal domains and jurisdictions (Bloodgood et al., 2014; Bolleyer, 2018; DeMattee, 2022). 13 We focused on freedom of assembly, association, and expression. While the guarantee of these freedoms is critical to ensuring citizens’ right to opposition, which is constitutive of liberal democracy, their exercise can and has been justifiably limited to address or prevent serious harms to the liberal-democratic state (Ashworth and Zedner, 2014; Dahl, 1971: 4; Swiney, 2022). We developed one coding scheme per rights domain. 14 The specification of inventories of possible limitations in each was informed by a detailed assessment of cross-national, as well as in-depth, longitudinal studies focused on each rights domain, often conducted by legal scholars. 15 The total of 84 predefined coding categories 16 were formulated as questions with standardized, dichotomous answers that allowed trained coders analyzing original legislation to capture unambiguously the presence/absence (addition/removal) of those rights limitations in any given year over the 23-year period covered. 17
Building on previous comparative work on militant democracy that uses normatively anchored conceptual categories to assess legal frameworks (Ashworth and Zedner, 2014; Bourne and Casal Bértoa, 2017; Capoccia, 2001; De Leeuw and Bourne, 2020), we distinguish categories that only align with the broader substantive notion (and are not covered by the narrower procedural notion) from those that also align with the procedural notion. Based on Table 1, we considered, first, whether our coding categories address serious harm to the state, the democratic process, or liberal values, and second, whether this harm had to be manifest in concrete behavior or if the mere expression of beliefs, ideas, or intentions sufficed for coercive regulation to apply. Any coding category referring to legal provisions that countered harm manifesting itself only through expressed beliefs, ideas, or intentions was classified as justifiable only under the substantive conception – irrespective of the type of harm. The same goes for any category capturing rights limitations to address harm to liberal values – irrespective of its required manifestation. 18 Of the total of 84 categories, 51 capture limitations qualified as self-defense measures only within the broader substantive framework, while 33 also align with the narrower procedural notion. 19
Empirical analysis
Between 2000 and 2022, the 12 European states analyzed have progressively expanded their repertoire of countermeasures to protect the constitutive pillars of the liberal-democratic state, mostly by adopting limitations that can only be justified as self-defense under the broader, substantive conception. In line with our conceptualization of rights limitations (Table 1), we first analyze the types of harms countries have sought to address through these new limitations, revealing a distinct turn toward the defense of liberal values. We then examine the manifestation of harm they have sought to regulate – whether the expression of harmful beliefs, or only concrete, harmful behavior. We related these developments to central legal reforms and their drivers, such as domestic exposure to terrorist attacks and internationalization.
Figure 1 displays the evolution of rights limitations, contrasting those that qualify as justifiable countermeasures only under the broader, substantive conception of self-defense (dark gray area) with those that qualify under the narrower, procedural conception (light gray area), aggregated across countries and domains. 20

Evolution of right limitations over time: Breakdown of ‘procedural’ versus ‘substantive only’ countermeasures.
Exploring the extent to which liberal-democratic governments resort to formal-legal rights limitations to regulate their own societies, Figure 1 shows that the repertoires of countermeasures available to European governments have considerably broadened over the past two decades. This trend supports earlier research arguing that fundamental rights in democratic countries are increasingly regulated – even questioned and ‘restructured’ – in response to fundamental challenges such as security threats, public health crises, 21 and digitalization 22 (Ahmed, 2023; Dunne, 2007: 270; Sajó, 2004: 69; Zedner and Ashworth, 2019), as well as to the emergence of ‘new fundamental rights actors’, notably the EU (Imamović et al., 2024: 139). 23
While rights limitations on freedom of association, expression, and assembly have historically been a part of these democracies’ legal frameworks, the prevalence of both ‘procedural’ and ‘substantive only’ countermeasures has increased significantly over time. Notably, these developments hold true for all three legal domains examined, and tend to go hand in hand. The strengthening of national proscription regimes, a trend that has curtailed the scope of freedom of association in the entire region, especially following terrorist attacks in the early 2000s and mid-2010s, illustrates this parallel growth in ‘procedural’ and ‘substantive only’ self-defense measures (see on counterterrorism, e.g. Ashworth and Zedner, 2014; Bigo et al., 2015; Epifanio, 2011; Roach, 2004). European governments often introduced new grounds to prohibit groups based on concrete anti-state behavior – justifiable under both notions – alongside ancillary bans based on mere intention, aspiration to, or glorification of the defined behavior – belief-related conducts that are insufficient to justify rights limitations under the procedural conception (on this ‘preventive turn’ in legislation, see e.g. Ashworth and Zedner, 2014; Sajó, 2004: 69). Most notably, terrorism and its glorification are now grounds for banning organizations in almost all countries, with the exception of Greece, which has introduced a wider limitation by banning groups for the intention to use, aspiration to, or glorification of violence. Undoubtedly, the EU’s expanding counterterrorism policy, exemplified by Council Framework Decisions – notably 2002/475/JHA on Combating Terrorism and its 2008 Amendment, 2008/919/JHA – has played a role in the convergence observed here. These instruments required some legal harmonization across countries, providing, inter alia, for the criminalization of incitement to terrorism and provocation to commit terrorist acts (Bigo et al., 2015; Den Boer and Wiegand, 2015). 24
While all domains display growth, the domain of freedom of expression – a historically tightly regulated area on the continent (Bleich, 2011: 17–43) – stands out for experiencing proportionally greater changes in both ‘procedural’ and ‘substantive only’ countermeasures. In line with earlier literature on the increasing complexity of free speech laws (Barendt, 2007; Bleich, 2011), this trend not only makes the domain a key driver of the patterns observed in Figure 1, but also indicates a degree of regulatory convergence across countries. Influenced by the EU framework decision issued in 2008 on the matter 25 (Casarosa, 2021: 12–15), such convergence reflects similar legislative changes targeting hate speech, both in its concrete manifestations (e.g. incitement to violence against sexual minorities and persons with disabilities, which by 2022 had become punishable offenses in nine countries), and in its ideational ones (e.g. insulting speech directed at these groups, restricted in seven countries). By contrast, the domain of freedom of assembly 26 has had the proportionally lowest number of countermeasures of both types, and legal changes in this area have been more gradual and diffuse. Although relatively stable until 2018, countries such as Hungary, Greece, and Latvia have since introduced reforms to their assembly regulations aimed at limiting both concrete behavior (e.g. dispersal due to actions against the state) and the expression of ideas at odds with liberal values. For example, Hungary has restricted manifestations held in dates and locations related to the Holocaust, World War II, and communism (on the symbolic import of dates and locations, see Salát, 2015: 51–53). While changes in this domain have long appeared to be driven by domestic concerns, the recent cross-national trend toward increasing limitations resonates with renewed public and academic debates about the role of protest in democracy (Fishman, 2025: 94; Stokes, 2020), and with accusations of a rising pattern of attacks on the right to peacefully protest in Europe – including attacks on the ideational content of specific protests. 27
Further zooming in on country patterns confirms that the overall expansion of repertoires of countermeasures seen in Figure 1 is not driven by individual cases, providing additional evidence that common factors – notably, counterterror efforts and the EU – have influenced at least some legislative reforms across cases. 28 In all 12 countries studied, the level of rights limitations was higher in 2022 than in 2000, and in most cases this expansion involved the introduction of legal provisions in line with both the procedural and substantive notions. However, as we discuss in more detail below, country patterns differ in terms of the overall level of rights limitations that countries had ‘on the books’ in 2000. Moreover, the extent of longitudinal change considering both ‘procedural’ and ‘substantive only’ countermeasures is more pronounced in Latvia, Hungary, Malta, and Greece, followed by Austria and Poland. That most of these are newer democracies and EU member states suggests that this pattern may reflect a shared ‘catching-up’ effect. However, the overlap of this group with countries – most notably Hungary – where autocratization tendencies have been observed calls for caution when evaluating the factors triggering these changes – a subject we explore below in relation to limitations on the expression of beliefs.
An examination of the political forces behind legal changes in the three domains considered shows that in most cases, populist right-wing government parties – typically characterized by authoritarian views and a preference for restrictive, punitive policies (Mudde, 2007) – were not key, direct drivers of new provisions limiting rights to protect the liberal state, even in more security-oriented areas, such as counterterrorism legislation. Aside from Hungary, where the Fidesz government in power since 2010 adopted a range of rights limitations, these changes were chiefly adopted by mainstream political forces, echoing earlier case-oriented research, which shows that, in response to various threats, mainstream governments have adopted a breadth of self-defense measures (e.g. Bolleyer et al., 2025; Fishman, 2019). 29
Importantly, Figure 1 indicates that the growth of ‘substantive only’ countermeasures was more pronounced than that of ‘procedural’ ones, suggesting that the legal architectures of European democracies have not only become more robust in terms of self-defense. They have also come to support an increasingly broad notion of liberal-democratic self-defense, aligned with the substantive conception, in which the state seeks to protect more than the rules of the democratic game and actively defends liberal values, when necessary, limiting the expression of ‘harmful’ ideas. To explore this progressive change, Figure 2 zooms in on this pattern and presents the cumulative growth of each countermeasure type in relation to the initial year of observation, 2000.

Cumulative percentual growth of ‘procedural’ and ‘substantive only’ countermeasures across all countries and domains in relation to 2000.
Figure 2 reveals that although we see increases across the board, since 2005 countries have adopted relatively more new legal provisions that limit rights in line only with the substantive conception than those that are (also) in line with the procedural one. This pattern became more marked in the 2010s, driven mainly – as discussed – by the introduction of new provisions regulating freedom of expression and association. Since 2010, for example, many countries have adopted new legal grounds for restricting speech that denies, trivializes, or glorifies the Holocaust and other historical atrocities. In doing so, rather than solely addressing behavior that endangers the democratic process and the state – in line with a procedural notion – European democracies have increasingly sought to defend liberal values through regulating the expression of citizens’ illiberal or anti-democratic beliefs, protecting democratic society from speech deemed ‘harmful’ based on a specific normative stance. These new speech restrictions on harms to liberal values and on the manifestation of ideas that do not concretely endanger the democratic procedure can only be considered as justifiable countermeasures under the broader substantive conception of self-defense. Given that this qualitative shift toward a more expansive notion of self-defense potentially carries long-term empirical and normative implications for the resilience and quality of democracies, we now examine it more closely, exploring the extent to which states are now defending liberal values and regulating the expression of ideas that circulate in society.
Figure 3 shows the types of harm that rights limitations adopted over time by our 12 countries have been designed to avert. Rather than distinguishing between ‘procedural’ and ‘substantive only’ countermeasures, it presents the relative number of limitations addressing harm to the democratic process, the traditional focus of militant democracy research (Bourne, 2022: 491; Capoccia, 2019), in comparison to provisions countering harm to the state and to liberal values from 2000 to 2022. 30 Echoing Figure 2, the steady rise of ‘harm to liberal values’ indicates that European democracies have increasingly expanded their self-defense approach to protect liberal values, especially since the 2010s. While the number of provisions addressing all three harms has increased over time, the increase has been more pronounced for limitations targeting harm to the state and harm to liberal values, respectively. The sharper rise in the ‘harm to the state’ category reflects the adoption of legal provisions, partly influenced by the EU counterterror framework, to cope with terrorism and other public security threats (Bigo et al., 2015; Den Boer and Wiegand, 2015; Epifanio, 2011; Roach, 2004). This trend lends support to the idea that civil society is increasingly perceived as a potential security risk to the state (Sidel, 2008: 9). By 2022, there had been a high degree of regulatory convergence: nearly all countries had introduced new legal grounds to ban groups in order to protect the state from violence, terrorism, separatism, and unlawful behavior. In most countries, the intention to commit such acts and their glorification had also been criminalized. For instance, 11 countries criminalized speech supporting terrorism, and seven criminalized the glorification of terrorist acts. Although some countries have recently strengthened their assembly laws to protect the state, additional limitations on peaceful assembly remain limited. Beyond dispersals based on public order or safety, or the carrying of weapons, no other limitations countering harm to the state were present in a majority of countries in 2022.

Evolution of right limitations by type of harm (to the state, democratic process, and liberal values) across all countries and domains over time.
Figure 3 also indicates that, compared with more traditional rights limitations aimed at protecting the democratic process, those addressing harm to liberal values increased more over time. While none of the examined countries added, for example, ‘violation of basic democratic norms or values’ as a new ground for banning groups, several states expanded their proscription regimes to ban groups for discrimination, religious fundamentalism, and violation of broad international norms – all of which fall under ‘harm to liberal values’. Since the substantive template rests on a wider notion of harm and can justify limitations to rights as protective of liberal values, this considerable rise indicates that the countries analyzed – through changes to their legal architectures – increasingly embrace the broader, substantive notion of self-defense.
Further legal changes in this direction include, as mentioned, reforms in the legal domain of freedom of expression, with several countries adopting restrictions on various forms of hate speech and on genocide denial, particularly following the 2008 EU framework decision. In the domain of freedom of assembly, countries have also introduced restrictions on displaying certain symbols, signs, and chants during public meetings, especially those linked to controversial groups. These developments in the regulation of assembly parallel changes in speech regulation, as assemblies are inherently expressive and often rely on symbols to convey messages (Salát, 2015: 6–8, 265). Although most of these provisions are not yet present in a majority of countries – unlike those addressing harm to the state – some have become widespread. For example, by 2022 all countries except Germany, Ireland, and the United Kingdom allowed the proscription of groups on grounds of discrimination. Importantly, limitations countering harm to liberal values exist in all countries, and 10 of them have introduced new measures of this kind over the 23-year period, confirming that the shift observed in Figure 3 represents a shared trend. 31
The substantive conception justifies a wider range of rights limitations as measures of self-defense than the procedural one not only because it defines harm more broadly, but also because the state can counter harms preemptively by regulating the expression of ideas, beliefs, and intentions on a wider scale. To explore how European countries have addressed these manifestations of harm, Figure 4 compares the evolution of rights limitations adopted to counter harmful behavior (such as dispersing public assemblies due to actual violent behavior or public disorder) with those countering the mere expression of ‘dangerous’ ideas and beliefs (such as group bans based on the mere intention or aspiration to violate the constitutional order or values, or on the glorification of terrorism). 32 These measures might aim to counter harm to the state, to the democratic process, or to liberal values.

Evolution of rights limitations addressing harmful ‘behavior’ and those addressing the expression of ‘belief’ across all countries and domains over time.
Figure 4 shows that, in 2000, rights limitations addressing harmful behavior were more widespread than those regulating the expression of beliefs, which were initially less common. Both types have increased steadily since then. Compared with 2000, European states have become more willing to restrict the expression of beliefs, thereby extending the scope of self-defense beyond the political realm and the lives of individuals qua citizens to broader societal dynamics. Increasingly, the mere intention to engage in, or the glorification of, certain behaviors – not only concerning violence or insurgency against the state, but also discrimination and religious fundamentalism – is sufficient for states to limit the rights of association, expression, and assembly, even if such behavior does not materialize.
To be sure, while all countries have more limitations targeting the expression of beliefs by 2022, this trend is not uniform. As briefly mentioned, zooming in on the country-specific dynamics reveals two types of differences between the cases studied. First, country patterns relate to different ‘baselines’ from which countries started out. Second, the extent of longitudinal change is different across countries. Concerning the first difference, countries such as Germany, France, Italy, and Spain had more rights limitations on the expression of belief than others from early on. However, this is not the case for all older EU member states or long consolidated democracies. In 2000, the United Kingdom and Ireland stood out for their much lower number of limitations on the expression of beliefs. This discrepancy reflects earlier research on the enduring influence of state traditions on how European countries have governed their societies and regulated rights for many decades. Germany and France, with their statist traditions, grant state authorities the rights to proactively regulate and constrain society to implement public interests. Countries like the United Kingdom and Ireland are considered ‘weak’ states, which view government and the interests it pursues as a reflection of societal interests. They are thus much less inclined to regulate society (Birnbaum, 1988; Bolleyer, 2018; Bolleyer et al., 2025). Over time, Ireland and the United Kingdom maintained relatively lower levels of rights limitations on the expression of beliefs, whereas other countries that started with comparatively fewer limitations ‘caught up’, as discussed next. This suggests that deeply entrenched regulatory traditions continue to shape how these states legislate in the domains studied.
Regarding the second difference, as aforesaid, we observe more change in Latvia, Hungary, Malta, and Greece because they had fewer limitations in 2000, reaching levels similar to those of more regulated countries by the end of the period. This indicates a ‘catching-up’ effect, especially in newer democracies and EU member states. Greece stands out in this group in terms of both democratic age and EU membership. Its pronounced longitudinal change reflects the late introduction of counterterrorism legislation, mostly following international conventions, especially since 2002 (Chainoglou, 2017: 499). Austria also significantly increased the number of limitations on the expression of belief, even though it began from a comparatively high level of such limitations. Since 2012, the country introduced numerous additional limitations on the rights of expression and association, not only to counter hate speech and terrorism, but also to address religious fundamentalism. This development is consistent with the politicization of religion observed in the country since the mid-2010s (Mattes, 2021: 214–215) and linked to growing concerns around the governance of migration and social pluralism across Europe (Hutter and Kriesi, 2022; Mouritsen and Olsen, 2013).
Such noticeable regulatory developments impinging on the expression of beliefs and ideas – even in the absence of imminent harm – raise concerns due to their potential to undermine social pluralism, particularly when observed alongside more recent autocratizing tendencies in some countries and the far-right surge in Europe. Hungary, now an ‘electoral autocracy’, illustrates this point: while significantly expanding hate speech regulation in line with European standards, the Fidesz government has from the outset adopted a broader restrictive approach to freedom of expression. This included controversial media laws introduced under the guise of fighting hatred against both minority and majority groups, and later, specific speech limitations to protect the ‘dignity of the Hungarian nation’ and children from the depiction of LGBTQ+ identities (see, for an overview of these changes, Balogh et al., 2025). 33 This highlights the need to closely examine the contexts in which legal changes signaling a shift toward substantive self-defense occur, considering especially how these legislative innovations interact with other elements of the legal framework and how, together, they affect democratic quality – a subject we discuss in the conclusion (Scheppele, 2013, 2018).
Some of these developments, in particular the use of legal instruments to minimize risks and avert prospective harms to state security – as in the case of group bans based on the glorification of terrorism – echo literatures identifying a greater regulatory focus of Western states on security and preemptive legal measures in response to contemporary threats, especially post-9/11 (Roach, 2004; Tyulkina, 2015; Zedner and Ashworth, 2019). Nevertheless, though such preventive rights limitations are justifiable countermeasures under a substantive notion of self-defense, the literature also raises concerns about government overreach and the imposition of undue restrictions on citizens’ fundamental rights and civil liberties, especially if the scope and boundaries of legal instruments used are not properly defined, or if courts are unable to perform their duties (Sajó, 2006: 2290; Steiker, 1998; Zedner and Ashworth, 2019). Beyond the use of rights limitations on beliefs for state security reasons, the fact that governments in the region are increasingly empowered to interfere with the expression of beliefs by individuals and groups – whether by restricting the dissemination of degrading speech against minorities, vetoing public manifestations in places associated to ideologically charged events, or even banning the existence of organizations that promote illiberal and anti-democratic views – could also reduce the free circulation of ideas in the public arena, potentially curtailing pluralism and stifling the democratic debate (Capoccia, 2013: 213), even in countries that are not backsliding.
Conclusion
Amid a growing number of fundamental rights limitations adopted by elected governments in Europe to counter internal challenges, and given the paucity of systematic, cross-national research on this phenomenon, we have investigated the extent to which 12 European countries’ legal architectures have successively incorporated new rights limitations formally designed to address serious harms to the liberal-democratic order. Covering the period 2000–2022, we assessed their evolving nature along two dimensions: first, by the type of harm that newly adopted provisions address (distinguishing between harm to the state, to the democratic process, and to liberal values); and second, by the manifestation of harm required in provisions for state authorities to interfere with fundamental rights (distinguishing between concrete harmful behavior and the expression of harmful beliefs).
Our findings show that these countries’ repertoires of rights limitations in the domains of freedom of association, assembly, and expression have generally expanded and diversified, with a particularly pronounced growth in measures targeting harm to the state and to liberal values. While differences in democratic age, legal tradition, and EU membership inform country-specific patterns of legal change, countries’ legal architectures nevertheless converged responding to common pressures, such as Europeanization and the crisis of terrorism. Reflecting attempts to regulate growing societal pluralism, states have increasingly introduced countermeasures that limit the expression of harmful beliefs, as most noticeable in the case of counterterrorism measures designed to both avert imminent threats and pre-emptively target dangerous speech and groups. Since 2005, countries have introduced relatively more measures compatible only with a more expansive, substantive notion of self-defense. Due to the strengthening of hate speech regulation across the EU, nearly all states adopted additional legal provisions that aim to protect liberal values by limiting the substantive content of speech, as exemplified by the criminalization of publicly condoning or denying historical atrocities. In some cases – particularly among newer member states – these changes seem to reflect efforts to meet EU standards in this area. We identified more nuanced, but similar developments in the other domains as well. Even the regulation of assembly has been subject to greater limitations on the locations and calendar dates in which public meetings may be held, not to mention more recent, direct content restrictions on protests.
In essence, over the past two decades, European democracies’ legal frameworks have increasingly aligned with a substantive notion of liberal-democratic self-defense, in which the state is granted the power to proactively defend liberal values and limit the expression of ‘harmful’ ideas. Thus, we see an expansion of the formal-legal conditions under which state authorities can interfere with pluralism and individual rights, arguably to protect liberal-democratic institutions and values from societal actors deemed detrimental to the latter. Considering this expansion’s broader implications for democracy in Europe, it is important to stress that the growth of rights limitations at a government’s disposal is not in itself necessarily conducive to either democratic resilience or democratic erosion. The consequences of these developments critically depend on how these legal tools are used in specific settings. The notion that the government’s capacity to limit rights in the name of liberal values can yield protective consequences is fundamentally premised on the assumption that governments entrusted with the promotion of such values remain committed to them (Issacharoff, 2007: 1442; Loewenstein, 1937b: 654). Although the legal changes described above were chiefly adopted by mainstream governments, the rise of illiberal parties and leaders to power in democracies whose consolidation was long taken for granted has made this critical assumption increasingly problematic. Then, provisions designed to counter rights abuses by citizens might be exploited by authorities to deliberately further democratic erosion (Graber, 2024; Invernizzi-Accetti and Zuckerman, 2017; Issacharoff, 2007; Rak and Bäcker, 2022). Alternatively, judicial constraints can play a critical role (domestically and internationally) in mitigating executive overreach when limiting rights, arguably, to protect the liberal-democratic order (Kirshner, 2019: 66).
Relatedly, understanding the consequences of expanding self-defense measures for the resilience of a particular democratic order requires not only establishing whether and how individual provisions are implemented and against whom (Bourne, 2024). 34 We also need to move beyond fundamental rights regulation as a single dimension of countries’ rights infrastructure and approach the ‘legal order as a system with interacting parts’ (Scheppele, 2013: 562), situating the evolution of rights limitations in a broader reform context. The considerable growth of self-defense provisions across legal domains, as exemplified by Hungary under the rule of Fidesz, forms part of a larger process that becomes visible once other alterations of the system’s legal architecture, such as judicial reform, are considered. As highlighted by Scheppele (2018: 548), only then might it become apparent that successive reforms might jointly generate a combination of rules that systematically erode accountability structures and individual rights protections constitutive for liberal-democratic states (Boda, 2023; Chaudhry and Heiss, 2022; Enyedi, 2024; Glasius, 2018).
Therefore, for future research to assess such expansion’s consequences for democratic resilience and erosion, two scenarios need to be distinguished. Even when implemented with restraint by ideologically liberal governments, in increasingly divided societies, the use of an ever wider range of coercive self-defense measures might not only generate societal backlash, but also enhance the radicalization and polarization that such measures were meant to help contain (e.g. Invernizzi et al., 2017; Börzel and Zürn, 2021; Malkopoulou and Moffit, 2023). In more normative terms, a well-meant expansion of rights limitations to shield liberal-democratic orders from serious harm also raises the fundamental question of to what extent and in what ways liberal democracy as regime type can still afford to grant fundamental rights to its citizenry in the longer term (Ashworth and Zedner, 2014; Sajó, 2006). As stressed by Fox and Nolte (1995) three decades ago, ‘theoretical discussions often reflect the very practical need of democratic societies to reassess and redefine their identities in times of crises’ (p. 21; Della Porta, 2013). In the long term, legal responses to increasing hostility to liberal-democratic values within pluralistic societies might transform the normative standards citizens expect liberal-democratic states to comply with in terms of which rights limitations are deemed acceptable and which are not (e.g. Davis and Silver, 2004; Sajó, 2006). This might broaden more and more the realm of justifiable rights limitations – and thus the leeway for legal government interference in fundamental rights.
Alternatively, illiberal parties might come to power and use preexisting rights limitations to legitimize invasive and anti-pluralist government action (Rak and Bäcker, 2022). Countering the glorification of harmful ideas to defend liberal values might constitute a legitimate and even necessary response to fundamental challenges liberal democracies are currently facing. But there are inherent dangers in an expansive understanding of how authorities can interfere with pluralism and individual rights to guarantee liberty. The ‘classic “who guards the guardian” dilemma’ highlighted in studies of non-democratic forms of ‘managed pluralism’ (Balzer, 2003: 192) becomes all the more salient in democracies, as they endorse a substantive notion of self-defense and are reliant on state authorities’ commitment to liberal values. To quote Shklar from a lecture on the notion of rights in liberalism she held decades ago in light of recent developments: we need to assume ‘that those public agents whose sole function is to protect the rights of citizens will not be tempted to abuse their just powers to create an illiberal regime. This is unhappily only a hope’ (Shklar, 2023: 292).
Supplemental Material
sj-docx-1-cos-10.1177_00207152261443932 – Supplemental material for Governments limiting fundamental rights: An expansion of liberal-democratic self-defense in Europe?
Supplemental material, sj-docx-1-cos-10.1177_00207152261443932 for Governments limiting fundamental rights: An expansion of liberal-democratic self-defense in Europe? by Nicole Bolleyer and Paula Guzzo Falci in International Journal of Comparative Sociology
Footnotes
Acknowledgements
The authors express their gratitude to the reviewers and editor of the International Journal of Comparative Sociology, as well as to the Special Issue editors, for their thoughtful comments. They also thank Hannah Laier and Celina Schneider for their excellent research assistance, and Valentin Daur for his support in preparing the dataset. The support of the European Research Council (ERC) is gratefully acknowledged. The views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them.
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research has received funding from the European Research Council (ERC) (Grant Agreement No. 101001458, CIVILSPACE).
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Supplemental material
Supplemental material for this article is available online.
Notes
References
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
