Refusing to take part in war is as old as war itself. This wide-ranging and original book brings together four different bodies of knowledge to examine the practice of conscientious objection: historical and philosophical analyses of conscientious objection as a critique of compulsory military service and militarization; feminist, LGBT and queer analyses of conscientious objection as a critique of patriarchy, sexism, and heterosexism; activist and academic analyses of conscientious objection as a social movement and individual act of resistance; legal analyses of the status of conscientious objection in international and national law. Conscientious objection is an increasingly important subject of academic and political debate in countries including the US, Israel and Turkey. This book provides a much needed introduction and tool for making sense of the history of nation-states in the 20th century and understanding the political developments of the early 21st century.