This chapter explores the intertwined concepts of war and peace in the political, religious and cultural frameworks of the ancient Near East, particularly in Mesopotamia and Assyria. It traces the evolution of warfare from early city state conflicts to the large-scale imperial campaigns of the first millennium BC. The text examines how war was legitimized through divine sanction, ritual practices and ideological narratives, portraying kings as divinely mandated warriors. It also details the organization of armies, military technologies and intelligence strategies, especially under the Neo-Assyrian Empire. Peace is presented not as the absence of war but as a condition imposed through treaties, vassalage and imperial control, often following conquest. The chapter highlights the theological and ritual dimensions of both war and peace, including divination, purification and treaty ceremonies. It concludes by addressing the human cost of war, the role of deportations, and the post-war integration of conquered peoples. Through a multidisciplinary lens, the chapter reveals how war and peace were central to statecraft, ideology and societal order in the ancient Near East.