This chapter reviews discourse analytic research within International Relations and Critical Discourse Studies which has examined post-Cold War and post-9/11 security discourses. Within International Relations, analysts have pursued a “critical geopolitics” by conceptualizing security as a discursive phenomenon open to interrogation and challenge. They have demonstrated the constitutive relationships between discourse, security, space, and identity. Within Critical Discourse Studies, analysts concerned with the socio-political nature of discursive practice have examined how the 9/11 attacks were discursively construed, the inter-discursive nature of post-Cold War security policy discourse, and the discourses of war, peace, militarism, and the global war on terror.