The chapter describes the contemporary history of efforts to manage risks to global financial stability. States seek to control the capital markets upon which they depend. But they sometimes also open them up, both to attract foreign investment capital and to provide outlets for national investments abroad. This makes them harder to control with national regulatory and supervisory policies and practices alone. Ever since the end of World War II, despite periodic crises and attendant backsliding, a trend toward capital market openness has gathered pace. Mindful of past sorrows, banks and other intermediaries, as well as the governments licensing and overseeing them, have sought new ways to cover the rising risks involved. Their joint project may accurately be viewed as an increasingly complex experiment in global reinsurance-as-governance. Unlike the nuclear case, the politics enabling it have been improvisatory, and relevant policy decisions have mainly been ad hoc in nature. This is explained by the sensitivity of the fiscal commitments implicated.