The central contention of this article holds that scholars do not adequately assess
and explain the influence of transboundary security issues on government behaviour.
Their assessment is not adequate because they do not fully conceptualize
the relationship between internal and external security concerns. Their
explanations are not adequate because existing theories cannot fully
explain how and why states respond to transboundary security issues. To rectify
these concerns, stimulate and structure further research, and encourage scholarly
dialogue, we build an analytical framework for (a) understanding what we describe as
the ‘nexus’ of internal and external security matters, and (b)
explaining why that nexus may change state behaviour on transboundary security
issues. The resulting framework encourages a strong focus on the nature of
transboundary problems before studying their implications for changes in
perceptions, policies, politics and polity.