Why do so many women organize against militarism and war? And why, very often, do they choose to do so in women-only groups? This original study, the product of 80,000 miles of travel by the author over a two-year period, examines women's activism against wars as far apart as Sierra Leone, Colombia and India. It shows women on different sides of conflicts in the former Yugoslavia and Israel refusing enmity, and co-operating for peace. It describes trans-national networks of women opposing US and Western European militarism and the so-called 'war on terror'.