POLINGO maps, analyses and theorizes the contribution of informal interpersonal networks to shaping the policies, programmes, and approaches of international non-governmental organisations (INGOs) in the international governance of crisis areas, particularly post-war states. By accompanying, complementing or even contradicting institutional linkages between state and non-state agencies, interpersonal networks transcend and bypass the conventional divide between governmental and non-governmental organisations. Since INGOs predominantly rely on their reputations as independent, disinterested and impartial to be able to work in post-war states, these closely knit interpersonal networks between state and non-state institutions raise questions regarding the sources and construction of legitimate INGO authority and credibility in global governance. Despite the ubiquity of such informal interpersonal networks, there has not been any systematic attempt to study their role in shaping, enabling or transcending institutional structures and means of cooperation in the global governance of post-war states. POLINGO addresses this gap by combining a longitudinal Social Network Analysis (SNA) with two in-depth qualitative case studies. The project breaks new ground theoretically and empirically by studying the institutional and interpersonal/informal interfaces between non-state and state-based forms of power in global governance as summarized in the following overarching research question: How do interpersonal networks between state- and non-state agencies shape INGO practices and positions in the global governance of post-war states?