Did Serbian, Croatian, Kosovar and Bosnian Diaspora influence US foreign policy in the Balkans? This is a legitimate question if one considers their activism at the end of the Cold War and the evolution of US foreign policy toward ex-Yugoslavia from 1989 to 1995. The American Congress is central to this analysis: it was from the start the focus of the various Diaspora groups’ lobbying efforts; and it was Congress which put pressure on the Executive with its historical vote to lift the embargo in Bosnia in July 1995. As we will see, it was the coalition of the various pro-Bosnian groups from various sectors of American society which strongly influenced congressmen. This coalition would not have happened without the mobilization and activism, as early as 1989, of the different « Yugoslav » Diasporas in the US.