Private International Law as Foreign Relations Law? Orienting Chinese Private International Law Towards Sustainable Development

Abstract

The Chinese Foreign Relations Law (‘the FRL’) – a collection of rules legalizing China's foreign policies – was enacted in 2023. While technically a set of policy goals and public law rules, it provides an opportunity to orient Chinese private international law (‘PIL’) towards sustainable development. Notably, the FRL connects Chinese PIL with sustainable development for the first time and revisits the conceptions of what is being understood as ‘domestic’ versus ‘foreign’, and ‘public’ versus ‘private’. This article explores how PIL can leverage this shift to accommodate sustainability as a normative value, foster positive interactions with foreign laws and courts, and develop a robust and tailored regulatory function. By doing so, Chinese PIL, as a form of foreign relations law, can expand its function beyond conflict resolution and develop a role in China's foreign policy and global sustainability governance.

I. Introduction

Establishing a mutually beneficial interaction between private international law (‘PIL’) and the United Nations’ Sustainable Development Goals ('SDGs’) has gained prominence in recent debates, ¹ a step considered critical to harnessing private power for the global agenda. Although PIL appears to have a complex and at times conflictual relationship with sustainability, ² it is contended that PIL has the potential to engage in global politics and therefore contribute to sustainability, ³ and the SDGs, in turn, can be approached from the perspective of directions and opportunities for transforming PIL, particularly that built on the Savignian model and influenced by liberalism, ⁴ on the other hand.

This article contextualizes the debate in Chinese law, exploring whether and how this mutual interaction might occur following the enactment of the Chinese Foreign Relations Law of 2023 (‘the FRL’). The FRL does not explicitly address PIL issues and is instead regarded as a set of political goals and public law rules. A connection between them, therefore, is not usually recognized or established. Nevertheless, this article attempts to conceptualize a connection where the FRL alludes to and entails the role of PIL in its provisions that involve a private aspect ⁵ and in its undertaking of establishing a solid system of foreign-related rule of law in China. Moreover, the FRL, representing a significant legalization of Chinese politics, provides a specific venue to project political agendas and substantive values onto Chinese PIL, aligning with Christopher Whytock's understanding of the role of politics in shaping PIL rules. ⁶ Against this backdrop, the FRL establishes sustainable development as an overarching goal in China's foreign policy, thereby influencing Chinese PIL in a specific direction with distinct requirements. In turn, PIL appears as a form of foreign relations law, a field of law which translates, expands, and puts to practice some of the wider norms and policies anchored in the FRL. Furthermore, the FRL revisits the relationships between the ‘domestic’ and the ‘foreign’, and the ‘public’ and the ‘private’ in structuring the Chinese system of rule of law in foreign affairs, which embodies China's approach to foreign relations in the legal field, ⁷ igniting the potential of Chinese PIL in promoting sustainability.

To elaborate on the above ideas, this article will unfold in three sections. The first section offers observations on the limited interaction between Chinese PIL and sustainable development before the enactment of the FRL, highlighting the need to engage Chinese PIL with sustainability and develop its capacities to do so. The second section elucidates the changes made by the FRL to the Chinese system of rule of law in foreign affairs, interpreting these changes as opportunities to orient Chinese PIL towards sustainability. While the orientation involves two steps – ‘connecting’ and ‘capacity building’, the second section also explains how the FRL connects Chinese PIL and sustainable development at the legal level. The final section follows to suggest how the approaches in the FRL to implement China's foreign policy can be applied in Chinese PIL, thereby allowing a fruitful contribution to sustainable development.

II. Private International Law and Sustainable Development in China: Limited Engagement Yet Great Potential

In the decades before the FRL, the interaction between Chinese PIL and sustainable development could only be seen in limited respects. China's system of PIL stands out as a codified framework, primarily rooted in the 2010 Law on Choice of Law for Foreign-related Civil Relationships, alongside provisions in the Civil Procedure Law of China. ⁸ Grounded in Friedrich Carl von Savigny's seat theory, Chinese PIL predominantly features multilateral choice-of-law rules that ‘neutrally’ determine applicable laws based on the idea of closest connection. ⁹ Influenced by economic globalization, it also provides an unrestricted scope of party autonomy in disputes over contracts, torts, and movables, ¹⁰ devolving power, to a very large extent, to private actors. Following the theoretical legacy of Savigny and international liberalism, Chinese PIL has long prioritized conflict justice and facilitating transnational transactions. ¹¹

Admittedly, an essential contribution of Chinese PIL to sustainability lies in its alignment with SDG 16 (‘Peace, Justice and Strong Institutions’) and should not be overlooked: it promotes access to justice and facilitates sustainable global interactions by providing a structured framework for resolving transnational disputes. Recent developments, most significantly the introduction of ‘other appropriate connections’ as a standard of jurisdiction, ¹² have further strengthened the link. However, the link of Chinese PIL to sustainability is predominantly institutional rather than substantive. Although Chinese PIL is not neglectful of substantive values, particularly in its emphasis on weaker party protection in conflict-of-law rules regarding family issues, ¹³ consumer contracts, and product liability, ¹⁴ this principle remains an exception to the closest connection principle and does not amount to a specific attempt to promote sustainable development. Thus, a clear and systematic connection between Chinese PIL and sustainability is yet to be established.

The connection is missing not only at the level of legal rules but also at the application level. Chinese PIL was not sufficiently capable of being employed to promote sustainability in practice. From the perspective of the relationship between PIL and sustainability, it is necessary for PIL to actively embrace a regulatory function in order to contribute to sustainability. This function is twofold, consisting of, firstly, PIL directly regulating parties’ behaviours through its rules advocating specific substantive outcomes of disputes (via ordre public and overriding mandatory rules); and secondly, PIL addressing the application of conflicting regulatory laws with substantive preferences, indirectly determining the outcomes. ¹⁵ Although ordre public and overriding mandatory rules are usually emphasized in Chinese PIL, ¹⁶ their application primarily reflects national considerations, encapsulated as ‘the basic principles of the laws … or the sovereignty, security, or public interest of China’ ¹⁷ and ‘the social public interests of the People's Republic of China’, ¹⁸ rather than global concerns such as those embodied in the SDGs. Therefore, under the current judicial practice, the application of ordre public and overriding mandatory rules in China offers limited contribution to sustainability outcomes and Chinese judges may hesitate to act contrary to the established practice. Moreover, Chinese PIL is centred around legal documents concerning a scope of ‘civil and commercial law’, which, in the context of Chinese law, is interpreted as equivalent to ‘private law’, generally blocking the possibility of applying Chinese PIL to conflicts involving regulatory laws. The widely debated judicial practice of proof of foreign law also impairedthe proper functioning of the weaker party protection principle in Chinese PIL. ¹⁹

Thus, there is little indication that PIL, in its current shape, is included in the legal toolbox of China to promote sustainable development, and sustainability, in turn, is not a particular concern of PIL and not part of its legal architecture. A link between them may exist, yet it remains indirect – procedural efficiency aids sustainable outcomes, but substantive environmental or social protections depend on the ‘neutrally’ found applicable law.

Nevertheless, the shifting of scholarly interests from classic PIL discussions to the relationships between PIL and substantive concerns suggests that PIL is neither naturally nor completely insulated from public agenda but can be instrumental after orientation. ²⁰ This also rings true for Chinese PIL and its contribution to sustainable development. Indeed, Chinese PIL has shown potential in its weaker party protection provisions which might help empower the vulnerables, and in the rules on overriding mandatory rules and ordre public, where the wordings capture a scope wide enough to embrace all sustainability concerns. Moreover, the applicable law rule of labour contract, which allows applying the law of the place from which the worker is posted, also deviates from the neutral stance and reflects substantive considerations. ²¹ It is indicated, accordingly, that Chinese PIL does not entirely reject substantive values and is not indifferent to the substantive outcomes of disputes. The scope of embracing substantive values could be broadened if deemed necessary or desirable. Besides, recent revisions to the Chinese civil procedure law have improved rules regarding parallel proceedings ²² and the grounds for refusing recognition and enforcement. ²³ The concept of reciprocity in recognition and enforcement of foreign judgements was also reinterpreted and broadened. ^{24 ,} The motives behind these moves are, intentionally or otherwise, consonant with ideas embedded in SDG 17 (‘Global Partnership’) while the adoption of a more open notion of reciprocity—grounded in mutual trust—reflects the very foundation of global partnership. Hence, it is reasonable to conclude that Chinese PIL can be aligned with sustainability though this will, by no means, be an easy process. It requires finding justifications and incentives from the politics as Christopher Whytock suggests that the shifting trajectory of PIL should be ‘ultimately traceable to politics’. ²⁵ Here, the FRL could be a game changer – as an important legalization of China's politics, it provides the specific venue to project political agendas and substantive values on Chinese PIL, offering chances to develop Chinese PIL's contribution to sustainable development. To substantiate this perspective, the following section primarily addresses two issues: first, how the FRL, which seems to fall within the public law area, implicates a private dimension; and second, how it orients PIL towards sustainable development.

III. The Foreign Relations Law's Vision of Chinese Private International Law: Sustainable Development as a Fundamental Goal

The FRL was enacted on June 28, 2023, with six general aims. ²⁶ It has been described as ‘the first fundamental foreign-related law that collectively elucidates the major policies, principles, positions and systems of China's foreign affairs and provides general rules on developing Chinese foreign relations’, ²⁷ which correctly highlights ‘collectiveness’ and ‘generality’ as the main features of the FRL – it provides general rules to collectively cover all aspects of foreign relations. ²⁸ This description also correctly identifies a primary reason why China opted for written law as the form of its foreign relations law, rather than the unwritten form in most countries: to consolidate and organize fragmented rules in China's foreign affairs at the level of law. ²⁹ In terms of the FRL's written content in 45 Articles, the FRL does not introduce many substantially new rules; instead, it mainly consolidates existing legal rules related to Chinese foreign relations and legalizes concepts previously outside the scope of law. For example, the consolidation is reflected in Article 10, 11, 12, ³⁰ serving to facilitate legal retrieval and further delineate the scope of existing rules that relate to foreign relations. On the other hand, the legalization process involves, as examples, Article 14, 26, 29, and 42, which formalize issues of institutional purview, foreign policies, and support systems as a legal basis for future executive and judicial activities.

Nevertheless, the FRL is significant from a broader perspective of Chinese foreign relations and policies, as it represents an essential effort by the Chinese legislative branch to echo the China Communist Party's call to build a robust system of foreign-related rule of law (the ‘SFRL’), ³¹ which is also translated as the ‘system of rule of law in foreign affairs’.

The SFRL is a creation of China's determination to develop foreign relations and implement foreign policies through a method of ‘rule of law’, which is in contrast with earlier approaches characterized by greater political flexibility. ³² The Chinese government aims to clearly define, at the level of law, what its foreign policies are and how the policies can and should be implemented. ³³ Thus, the concept of foreign-related rule of law was introduced into the China's rule of law discourse in ‘Xi Jinping Thought on the Rule of Law’ in 2020, associated with the concepts of domestic rule of law and international rule of law. ³⁴ While foreign-related rule of law is the goal, the SFRL serves as the institutional guarantee for achieving this goal. The SFRL is a system which encompasses all legal norms, regulatory frameworks, and implementation mechanisms relevant to foreign-related matters. ³⁵ The main stated purposes of the SFRL are to counter legal hegemonism and promote the construction of a fairer and more just global order through the rule of law, a method deemed to provide China with legitimacy and effectiveness in achieving these goals. ³⁶ The SFRL, therefore, embodies China's approach to foreign relations in the legal field, concerning the achievement of Chinese foreign policies. The FRL is designed to lay the foundation for the SFRL. Although the FRL was enacted by the Standing Committee of the National People's Congress rather than by the Congress itself, and thus not formally a basic law of China, ³⁷ it, clarifies fundamental ‘principles, concepts, and systems of foreign relations’ ³⁸ and is expected to function as a basic law within the SFRL to guide future legislative, executive, and judicial practice regarding foreign-related issues. ³⁹ How the FRL is formulated and plays its overarching role will reveal China's plan to structure and operate the SFRL in support of its foreign relations and policies.

The FRL generally answers the ‘what’ and ‘how’ (discussed in Section IV) questions concerning Chinese foreign policies mentioned above. Chinese foreign policies consist of objectives, principles, and courses of action regarding foreign relations, which are outlined in the Chapter Three of the FRL, ‘the Objectives and Missions of Developing Foreign Relations’, and Article 34. To illustrate, these Articles address China's global governance philosophy, ⁴⁰ its policy of opening up, ⁴¹ and the ‘Five Principles of Peaceful Co-existence’. ⁴² Sustainable development is implied within a framework of ‘glocalized’ ⁴³ concepts of sustainability, ⁴⁴ which is centred around the ‘Community with a Shared Future for Mankind’ ⁴⁵ and the Chinese philosophy of global development. ⁴⁶ The ‘glocalized’ concepts further encompass Chinese views on global security governance, ⁴⁷ human rights, ⁴⁸ common values of humanity, ⁴⁹ civilization diversity, ⁵⁰ climate governance, ⁵¹ and China's approaches to foreign aid and humanitarian cooperation and assistance. ⁵² These Chinese concepts translated sustainable development – a globally agreed holistic approach of growth and progress towards a sustainable world – into ideas more aligned with Chinese culture and tradition for better dissemination among the Chinese people while enabling a precise expression of China's sustainability concerns for more effective implementation. Through these concepts, sustainability is recognized as a crucial value in the SFRL and Chinese foreign policies.

The answer to how to promote the Chinese foreign policies can be understood at two different levels. This question, firstly, in general inquires about the scope of the legal tools to be employed for conducting foreign affairs, and more specifically, whether the available and effective legal tools are confined to public law or further include private law. Although foreign policy is generally deemed a public law issue, and thus the FRL has rendered most debates that centre around public (international) law implications and little evident interaction in practice between it and Chinese PIL has been observed, this article sees its intricate intertwinement with private (international) law. The very close connection between the FRL and Chinese PIL can be validated from both theoretical and systemic perspectives.

Theoretically, Karen Knop's perspective on foreign relations law as a ‘broader and finer normative net’ (than public international law) provides a very useful lens to understand Chinese PIL's involvement in the FRL. ⁵³ It could be understood following this perspective that the Chinese FRL is an essential attempt to weave a normative net called the SFRL. According to Knop, reducing foreign relations law to public international law would entail a significant loss, as public international law denies substate actors as legal subjects, overlooks domestic law issues, and thus merely sets the background conditions for foreign relations issues. ⁵⁴ The FRL and the SFRL, in the other way, highlight the roles played by enterprises, civil organizations and individuals in international exchanges and cooperation, ⁵⁵ and attach importance to domestic rules in a coordinated manner with transnational and international rules while implementing China's foreign policy. ⁵⁶ In this vein, the FRL resonates with Knop's contention that ‘(public) international law cannot generate the entirety of foreign relations law’, a field that ‘involves a more heterogeneous body of law’ and necessitates PIL as a component. ⁵⁷

Knop's net theory suggests foreign relations manifest their significance in implicating both public and private-law relationships across borders, and this idea can easily lead one's thoughts to Kennedy's famous diagnosis of ‘the decline of the public/private distinction’, ⁵⁸ which also finds illustrations in the FRL. As Kennedy observes, following social evolution, for example, the ‘expansion of state involvement in private areas’, and ‘stronger impact of private affairs on public interests’, there are increasing social scenarios and legal cases that cannot be clearly and meaningfully classified as ‘public’ or ‘private’, and this renders the distinction has transformed from an absolute dichotomy into a spectrum, or in Kennedy's own word, ‘continuum’, where most situations fall somewhere in between. ⁵⁹ In this way, the public/private distinction has been declining. This phenomenon has become even more striking in the international arena nowadays, since irresistible globalization permeates both public and private spheres and is in the process of intertwining them; thus, governments are increasingly challenged when relying exclusively on private or public law to develop their foreign relations that serve their foreign policies. ⁶⁰ The FRL is exactly produced in this complexion. And thus, the FRL, representing the legalization of foreign relations in China, becomes no longer absolutely public law or private law ‘but rather shares some characteristics of each pole’. ⁶¹ In this context, Chinese PIL, alongside public international law, can be approached as a form of foreign relations law capable of implementing Chinese foreign policies.

Systemically, PIL is integral to the Chinese SFRL, which the FRL establishes as its overriding goal, ⁶² and is functionally necessary for the SFRL to deliver expected results. The FRL plays a constitutional role in and structures the SFRL with two facets of foreign relations, ‘struggle’ and ‘cooperation’, ⁶³ corresponding to the two aforementioned purposes of the SFRL. ⁶⁴ While these two facets can be at times in conflict, this, meanwhile, presents the challenge of balancing ‘struggle’ with China's ‘Responsible Great Power’ narrative. ⁶⁵ Addressing the challenge makes it critical to coordinate domestic and foreign interests, and the solution is lying hidden among the ‘glocalized’ concepts of sustainability in the FRL, through which China expresses its commitment to deeper engagement in global sustainability governance while emphasizing local conditions to preserve domestic interests. The ‘glocalizing’ approach also suggests that the sustainable development of China and the sustainable development of the world are inseparable and mutually supplemented, resembling the relationship between the individual and the collective, ⁶⁶ which is incarnated in the concept of the ‘Community with a Shared Future for Mankind’. This approach is strengthened by the notion of ‘interdependence’ which emphasizes the mutual reliance or reciprocal influence between global structures and local actors. ⁶⁷ In sustainable development discourse, interdependence manifests as a two-way dynamic where global sustainability standards shape local practice while local innovations and interpretations simultaneously inform and transform global norms. Thus, global goals and local actions evolve in a structurally interlinked and mutually reinforcing manner. While local and global sustainability are interdependent and oriented towards a shared ultimate vision of a sustainable world, their so-called conflicts are not irreconcilable. Rather, they represent dynamic relationships where trade-off can be made in individual cases to achieve better long-term outcomes. In this context, China's ‘cooperation’ and ‘struggle’ narratives can be understood as reflecting a relationship of ‘goal’ and ‘means’. ⁶⁸ PIL is crucially important here, as it, while embracing and having the potential to reconcile unilateralism and multilateralism contains different techniques that allow for stressing the ‘local’ or the ‘global’ in a case-by-case manner. Moreover, PIL suggests a ‘think global, and act local’ approach, ⁶⁹ which takes local actions to achieve global impacts. While this approach aligns with and can facilitate Chinese foreign-related rule of law, which attempts to employ domestic rules to implement external policies and goals, PIL's importance to the SFRL and the FRL is again affirmed.

Furthermore, the FRL does not eschew its implications in the ‘private’ sphere, in its written content directly implicating PIL in terms of (anti-)anti-suit injunction, ⁷⁰ ordre public and overriding mandatory provisions, ⁷¹ and the treatment and legal status of foreigners. ⁷² Therefore, the private dimension is crucial to understand the full significance of the FRL.

Admittedly, Chinese PIL, as a form of foreign relations law and one component of the SFRL, is not automatically structured to fulfill every policy objective articulated by the FRL or the system. The FRL’s endorsement of sustainable development as a fundamental goal of China’s foreign policy does not, by itself, transform PIL’s doctrines or priorities overnight. However, it does create a normative framework and legal impetus that make it both possible and desirable to integrate sustainability concerns into PIL through conscious legislative and judicial choices. If Chinese PIL is structurally capable of contributing to sustainable outcomes, then it should be leveraged as part of China’s legal toolkit for advancing sustainability goals. In other words, the alignment of PIL with the FRL’s sustainability mandate is contingent, not automatic: it depends on deliberate institutional decisions and interpretative reasoning to infuse PIL with sustainable development values. By acknowledging this contingency while underscoring PIL’s capacity and the FRL’s guiding role, here presents a balanced yet persuasive case that Chinese PIL — though only a part of the SFRL —can and should embrace sustainable development as a normative goal. In this way, a potential link between Chinese PIL and sustainable development is for the first time created at the legal level. Their relationship in practice can resemble and learn from the interaction between the Preamble and the Articles of the Brussels 1 bis Regulation and the Rome Regulations, ⁷³ which suggests employing sustainability to guide the making, revision, interpretation, and application of the rules of Chinese PIL. To illustrate, invoking ordre public should take into account the impact of the application of foreign law on sustainable development, and regulations that significantly affect sustainability may be characterized as a type of the overriding mandatory rules and be directly applied. ⁷⁴ Another example is the applicable law to disputes over posting of workers, which is covered by the general contract conflict-of-law rule ⁷⁵ but Chinese PIL also provides the law of the place from which the worker was posted as a potential choice but without giving a specific trigger, ⁷⁶ leaving room for judicial discretion. Now with sustainable development as a guiding principle can enhance legal certainty: if that law can better protect the interests of posted workers, a concern particularly under SDG 8 (‘Decent Work’), judges are likely to prioritize it over the law of closest connection or even the chosen law.

IV. Rethinking Basic Conceptions in Chinese Private International Law: A Pursuit for a Robust and Tailored Regulatory Function

The other line of the FRL's answer to the ‘how’ question of China's foreign policy implicitly aligns with the ‘inward’ and ‘outward’ features of foreign relations law proposed by Campbell McLachlan in his theory of ‘Allocative Function’. ⁷⁷ As McLachlan argues, foreign relations law provides ‘a set of rules that allocate jurisdiction and determine applicable law in cases involving the external exercise of the public power of states’. ⁷⁸ It does so in three dimensions ⁷⁹ : first, between the organs of government; second, between states; and third, between the municipal and the international plane. The FRL internally addresses the first dimension of its allocative function in Chapter Two, ‘Scope of Power Concerning Foreign Relations’, by delineating the purviews of official entities regarding foreign affairs, ⁸⁰ such as the National People's Congress, the President, the State Council, and the Central Military Commission. Externally, the FRL, while briefly addressing the third dimension of allocative function in Article 30 to clarify the relationship between international treaty and the Chinese constitutional law, ⁸¹ primarily contributes to the second dimension of allocative function, focusing on the interaction between domestic law and foreign law, where it brings a revisit to the ‘domestic’ and the ‘foreign’, and the ‘public’ and the ‘private’.

How a country perceives the interaction between domestic law and foreign law, first, depends on its understanding of the ‘domestic’ and the ‘foreign’ – for example, the perceived dynamics between domestic and foreign affairs determines whether and to what extent domestic and foreign law should interact. In this regard, affirming the increasingly intertwined internal and external affairs, ⁸² Article 29 of the FRL introduces a coordinated approach to domestic rule of law and foreign-related rule of law, ⁸³ replacing the previous epistemology and methodology that contrast the ‘domestic’ and the ‘foreign’ ⁸⁴ and promoting their positive interaction and mutual development. ⁸⁵ This coordinated approach, while recognizing the equal strategic importance of the two types of rule of law, requires commensurate efforts and resources to be invested in developing foreign-related legal rules which has historically lagged behind the domestic ones. ⁸⁶ This approach also rejects the practice of differentiated application of legal rules in domestic and foreign cases, a practice akin to the foreign affairs exceptionalism proposed by Curtis Bradley, ⁸⁷ and attempts to limit improper executive and judicial discretion in foreign cases. ⁸⁸ This reconceptualization has already begun to materialize in judicial practice. Following the FRL, the Supreme People’s Court issued a new judicial interpretation on the application of international treaties and practices in foreign-related civil and commercial cases. ⁸⁹ This interpretation explicitly provides that international treaties shall, in principle, prevail over conflicting provisions of Chinese domestic law, ⁹⁰ and allows the application of treaties not formally binding on China when voluntarily chosen by the parties, so long as they do not contravene China’s mandatory laws or public interests. ⁹¹ Furthermore, the FRL seeks to find commonalities and a balance between domestic and foreign interests, embedding national interests into the framework of ‘the fundamental principles of international law and fundamental norms governing international relations’ ⁹² and the concept of the ‘Community with a Shared Future for Mankind’.

The ‘public’ and the ‘private’, on the other hand, determines whether the interaction between domestic and foreign law should take place in public law or private law, or both.

The FRL maps a wide range of foreign relations issues, spanning economics, culture, and politics, ⁹³ and involves not only state institutions but also NGOs, enterprises, and citizens as the legal subjects ⁹⁴ ; thus, in the context of the FRL, foreign relations are understood as encompassing both governmental and non-governmental relations. ⁹⁵ Cross-border interactions among public institutions, private organizations and individuals are considered crucial for realizing Chinese foreign policies. Consequently, legal tools to regulate, enable, and facilitate these interactions – encompassing both public and private law – are emphasized in the Chinese discourse on foreign relations law. In this vein, the FRL integrates the ‘public’ and the ‘private’, breaking down the division between them and reconfiguring them in a complementary way to serve shared goals.

The FRL's revisit to the two pairs of basic conceptions will by no means limit its influences to the rules and application of the FRL but aims to sweep the entire SFRL. Thus, Chinese PIL, as a form of foreign relations law operating under the framework of the SFRL, is supposed to reflect the FRL's formulation of the ‘domestic’ and the ‘foreign’, and the ‘public’ and the ‘private’. This, in turn, will allow Chinese PIL to enhance its ability, more specifically to develop its regulatory function, ⁹⁶ to contribute to solutions for the world's green transition and new geopolitical tensions.

To echo attempts and efforts are made to reconcile the ‘domestic’ and the ‘foreign’, Chinese PIL should improve in three aspects. Firstly, when domestic courts apply foreign laws, the proof of foreign law ⁹⁷ – which has long been a challenge for transnational civil and commercial litigations in China ⁹⁸ – should be improved. Fortunately, this issue has been recognized, and a judicial interpretation focusing on the proof of foreign law was enacted following the promulgation of the FRL. ⁹⁹ While this new judicial interpretation manages to address many loopholes of the proof of foreign law system in China, the issue of failed proof of foreign law remains unresolved. ¹⁰⁰ Nevertheless, also in response to the FRL and the SFRL, newly established proof of foreign law platforms are spreading across the country, ¹⁰¹ which might facilitate the proof of foreign law in practice and mitigate the issue.

Secondly, when domestic laws conflict with foreign laws, a homeward trend should be avoided. Chinese judges’ reluctance to apply foreign laws has raised great concerns from the academics. ¹⁰² This homeward trend risks obstructing the development of a sustainability-endorsing PIL, especially in cases where the applicable foreign laws provide a higher standard of protection for the interests at stake and could therefore better promote sustainable development, but are simply disregarded due to unfamiliarity and the cost of proving them. Therefore, Chinese PIL should promote a more open-minded application of foreign laws that may better serve sustainable development, and develop elaborated procedural rules for the ascertainment of foreign law to ensure a solid institutional framework. ¹⁰³ Nevertheless, when encountering improper extraterritorial application of foreign law— a country’s domestic regulations being enforced beyond its borders in a manner that contravenes international law or infringes upon another state’s sovereignty — Chinese PIL can, and in fact should, make use of blocking statutes to resolve the conflict. ¹⁰⁴

Thirdly, when domestic courts conflict with foreign courts, usually known as ‘parallel proceedings’, ¹⁰⁵ it necessitates improving rules and practice on forum non conveniens, anti-suit injunction, and the recognition and enforcement of foreign judgements. The Chinese forum non conveniens rule has been controversial since its formalization due to its excessively high threshold for application. ¹⁰⁶ Anti-suit injunctions are lacking in Chinese PIL. The Chinese system of recognition and enforcement of foreign law is relatively better than the two above, especially after the introduction of legal and presumptive reciprocity to replace the requirement of factual reciprocity. However, whether it can properly and effectively block foreign judgements that would result in unsustainable outcomes remains a challenge. Furthermore, Chinese PIL in this regard will also benefit from an active engaging in the Jurisdiction Project at the HCCH, which aims to address parallel proceedings as a particular concern.

As regards the ‘public’ and the ‘private’, which are approached in a complementary manner, Chinese PIL can respond in two ways. On the one hand, Chinese PIL should be more open and find efficient ways to accommodate the ‘public’, substantive values. ¹⁰⁷ There exist two ways to embrace substantive values, explicitly and implicitly. Explicitly, Chinese PIL can incorporate preferences in determining the applicable law, such as prioritizing laws that protect the vulnerables. In this approach, Chinese PIL can extend what has been termed ‘result-selectivism’ beyond marital and family issues to other types of disputes; ¹⁰⁸ and further refine existing rules to clarify the standards for identifying weaker parties and interpreting ‘(the law) favoring (the rights of the weaker party)’. ¹⁰⁹ Implicitly, Chinese PIL can grant the weaker party the right to choose the applicable law, as seen in the rules on consumer contracts and product liability. ¹¹⁰ This method can also be extended and refined in the area of jurisdiction, allowing plaintiffs, as the weaker party, to choose among different courts or defendants, and among different methods of bringing their lawsuits. Notable examples include proceedings against a parent company and cross-border class actions.

On the other hand, Chinese PIL should challenge the public law taboo, ¹¹¹ coordinating regulatory competition and conflict. ¹¹² Since regulatory law has become a key instrument in achieving political and public policy goals, PIL must find ways to interact with such rules if it is to contribute meaningfully to sustainability. This requires moving beyond the notion of PIL as an isolated and closed private law discipline and recognizing its potential to serve as a wisdom and technique for managing legal diversity — including conflicts of (not only private but also public) laws. ¹¹³ A more open and functional approach could enable Chinese PIL to not only support the extraterritorial application of transnational regulations but also respond effectively overlapping regulatory claims, ¹¹⁴ thereby advancing globally shared policy objectives such as those expressed in the SDGs.

V. Conclusion

The Chinese FRL of 2023 marks a pivotal turning point for orienting Chinese PIL towards sustainable development, transcending its traditional confines as a mere technical apparatus for resolving cross-border private disputes. Not only does the FRL embed sustainability as a normative goal in China's SFRL, but it also bridges the conceptual divides between the ‘domestic’ and the ‘foreign’, and the ‘public’ and the ‘private’, offering Chinese PIL solid ground to develop its regulatory function. This article has elucidated how the FRL connects Chinese PIL to sustainability at a legal level and proposed concrete pathways – improving foreign law application, countering homeward trends, refining jurisdictional rules, and embracing public regulatory values – to align PIL with China's broader foreign policy objectives. These steps position Chinese PIL as a dynamic instrument of foreign relations law and enhance its capacity to facilitate sustainable outcomes, echoing the FRL's dual narrative of ‘struggle’ and ‘cooperation’.

Beyond summarizing these findings, this orientation invites a broader re-examination of the evolving role of PIL in global legal governance. As it evolves into a regulatory mechanism capable of shaping international legal discourse, an increasing number of states may deploy PIL as a vehicle for advancing substantive policy objectives. These objectives, under the ‘glocalizing’ approach adopted by more states in navigating the green transition and geopolitical tensions, could overlap with state-driven policy goals and diversify significantly. In this regard, the regulatory function of PIL may raise concerns about intensifying conflicts. Yet, whether this evolution will foster greater global legal coherence or deepen normative fragmentation remains uncertain, one thing is clear: PIL's role in shaping the legal landscape of sustainable development is no longer a peripheral consideration, but an essential dimension of contemporary legal strategy.