The book presents the international laws on the use of force whilst demonstrating the unique insight a feminist analysis offers this central area of international law. The book highlights key conceptual barriers to the enhanced application of the law of the use of force, and develops international feminist method through rigorous engagement with the key writers in the field The book looks at the key aspects of the UN Charter relevant to the use of force - Article 2(4), Article 51 and Chapter VII powers - as well as engaging with contemporary debates on the possibility of justified force to meet self-determination or humanitarian goals. The text also discusses the arguments in favour of the use of pre-emptive force and reflects on the role feminist legal theories can play in exposing the inconsistencies of contemporary arguments for justified force under the banner of the war on terror. Throughout the text state practice and institutional documentation are analysed, alongside key instances of the use of force. The book makes a genuine, urgently needed contribution to a central area of international law, demonstrating the capacity of feminist legal theories to enlarge our understanding of key international legal dilemmas.