Abstract Ad hoc coalitions (AHCs) have been a persistent feature of global governance. However, only recently have they become the focus in governance scholarship. Why are they created, and how do they vary in their composition and afterlife? We examine AHCs since 1919 across health and security governance challenges. Our analysis rests on archival material from international organizations (IOs) and national governments. We argue that, in bringing together political rivals, AHCs serve three primary purposes. Firstly, as agenda setters, they address new governance challenges. Secondly, as capacity generators, they reshuffle membership compositions. Finally, as decision accelerators, they enable their members to bypass existing IOs. Beyond these commonalities, notable differences exist that are rooted in relative issue salience. Less salient issues are often led by bureaucrats and experts, glossing over political agendas and mediating between rivals. This set-up often leads to permanent cooperative structures. Issues that decision-makers perceive as highly salient occupy the attention of politicians who want to keep the coalition small. As a result, rivalries can easily come to the fore, leading to short-lived coalitions. Overall, AHCs point to more or less exclusionary action that serves as a testing ground for international cooperation in times of uncertainty and (geo)political crises.
Hofmann et al. (Tue,) studied this question.