This diverse collection of essays is the first to specifically engage Michel Foucault on questions of politics, security and war. It is also the first to take up the provocations found in Michel Foucault's recently published Collège de France lectures, particularly Society Must Be Defended, Security, Territory, Population and The Birth of Biopolitics. The contributors reassess the way Foucault worked experimentally and in collaboration and dialogue with others. In so doing, the essays pursue lines of enquiry that Foucault briefly extolled but did not exhaust, and take him in directions that he could not have foreseen, including the War on Terror, risk, biosecurity and biopolitics, AIDS, racial and ethnic conflict, and the critique of law. Foucault on Politics, Security and War is an essential contribution to Foucault scholarship and also poses wider challenges to political theory, international relations, security studies and legal theory.