Institutions as swords and shields: multilateral counter-terrorism since 9/11

International institutions are prominent in the 'global War on Terror'. But there remains variation in the institutionalisation of counter-terrorism, across policy domains and over time. I argue that institutions pursue tasks of counter-terrorism when they are backed by power. Institutions function as 'swords' as strong states seek to influence others. Weak states, too, are sensitive to the distributional consequences of cooperation and use institutions as 'shields' to resist the powerful. These claims are reflected in patterns of cooperation within the UN, and in terrorist financing and maritime security. Looking forward, multilateral counter-terrorism may remain contingent upon state power.