This thesis challenges the prevailing academic and journalistic consensus that ASEAN states, bound by a cast-iron norm of non-interference, do not intervene in other states’ internal affairs. It argues that ASEAN states have frequently engaged in acts of intervention, often with very serious, negative consequences. Using methods of critical historical sociology, the thesis reconstructs the history of ASEAN’s non-interference principle and interventions from ASEAN’s inception onwards, drawing on sources including ASEAN and UN documents, US and UK archives, and policymaker interviews. It focuses especially on three case studies: East Timor, Cambodia, and Myanmar. The thesis argues that both the emergence of ideologies of non-intervention and their violation can be explained by the social conflicts animating state policies. Non-interference was developed by embattled, authoritarian, capitalist elites in an attempt to bolster their defence of capitalist social order from radical challenges. Where adherence to non-intervention failed to serve this purpose, it was discarded or manipulated to permit cross-border ‘containment’ operations. After communism was defeated in the ASEAN states, foreign policy continued to promote the interests of dominant, state-linked business groups and oligarchic factions. Non-interference shifted to defend domestic power structures from the West’s liberalising agenda. However, ASEAN elites continued meddling in neighbouring states even as containment operations were discarded. This contributed to the collapse of Cambodia’s ruling coalition in 1997, and ASEAN subsequently intervened to restore it. The 1997 Asian financial crisis dealt a crippling blow to ASEAN. To contain domestic unrest in Indonesia, core ASEAN states joined a humanitarian intervention in East Timor in 1999. In the decade since, non-interference has been progressively weakened as the core members struggle to regain domestic legitimacy and lost international political and economic space. This is expressed most clearly in ASEAN’s attempts to insert itself into Myanmar’s democratisation process after decades of failed ‘constructive engagement’.

While not uncontested, the finding that liberal democracies rarely, if ever, fight wars against each other represents one of the seminal discoveries of international relations (IR) scholarship. Nevertheless, 'democratic peace theory' (DPT) – the body of scholarship that seeks to explain the democratic peace finding – still lacks a satisfactory explanation for this phenomenon. In this thesis, I argue that a primary source of this failure has been DPT's failure to recognize the importance of collective identification and trust for the eventuation of the 'liberal peace'. Building on existing DPT scholarship, most of it Realist or Rationalist in its inspiration, but also employing insights from Constructivist and Cognitivist scholarship, I develop a new model of how specific forms of collective identification can produce specific forms of trust. On this basis, I elaborate a new explanation of the liberal peace which sees it as arising out of a network of trusting liberal security communities. I then elaborate a new research design that enables a more rigorous and replicable empirical investigation of these ideas through the analysis of three historical cases studies, namely the Canada-USA, India-Pakistan, and France-Germany relationships. The results of this analysis support the plausibility of my theoretical framework, and also illuminate four additional findings. Specifically, I find that (1) IR scholarship needs a more nuanced understanding of the interaction between agents and structures; (2) 'institutionalized collaboration' is especially important for promoting collective identification; (3) DPT scholarship needs to focus more attention on the content of the narratives around which collective identification takes place; and (4) dramatic events play an important role in collective identification by triggering what I term catharses and epiphanies. I close the thesis by reviewing the implications of my findings for IR and for policymakers and by suggesting some areas worthy of additional research.