The Changing Concept of War and America’s Defence Policy

States fight by nature to get their hegemony accepted. Therefore, world history begins with wars and con-flicts. Unequal power exchanges between states have existed since the day humanity began to live together. Since the states reveal these dynamics, establishing sovereignty has survived from the first generation to the present. So why did societies that want to domi-nate each other find the solution in conflict and war? This study attributes this problem to the invariance of human nature, such as Thucydides, and a dogmatic reason in the consciousness of increasing humanity’s powers through fear. Although progress has been made in line with the systematically changing theories of war with the lessons learned from the methods of war between the Spartans and the Athenians, the following fact must be revealed: “Even if the technological development and economy of mankind progress, the war that this man dogmatically carries in does not change his nature, it only changes the methods of war.” This study reveals the change in war policies and defence in line with the data obtained by observing the conditions of American-based change of the political order transitioning to multipolar world order