This chapter provides a discussion on cosmic war in religious traditions, focusing on the development and evolution of cosmic war in the Hebrew Bible. Cosmic war can allow belief in the direct intervention of a deity on the battlefield on behalf of the deity's tribe, nation, or peopl, and is a concept that is profoundly settled in the religious traditions of the ancient Near East. The major themes found in most cosmic war traditions are elaborated. The wars in Afghanistan and Iraq rapidly play the tenor of a cosmic conflict against demonic forces. It must be noted that behind the cosmic impulse, there often lurks very real and earthly grievances that must be considered if the drive toward cosmic war, which remains such a destructive factor in contemporary religious disputes, is to be stemmed.