In the aftermath of Britain's 2016 decision to leave the EU, the Irish-American ethnic lobby remobilized to defend the Belfast/Good Friday Agreement from the threats posed by Brexit.

Drawing on interviews in Washington, Belfast, Dublin and London, in this book the authors explore how the lobby shaped US policy towards Brexit in order to prevent the reimposition of a hard border on the island of Ireland and preserve peace. The authors also consider the lobby's approach to other contentious issues, including a united Ireland and Troubles-related investigations.