Its not just one theory. The resemblances are derived from overlapping deep assumptions about politics. International politics as a zero- sum game: most important conflicts that take place are zero- sum. If i win you lose, if i win you give me blah. Each side has to be ready to protect its interests: eg. Instituted new rules to limit conflict in europe and to protect state sovereignty: eg. Napoleonic wars (1799- 1815): struggle for hegemony gives way to 19th century balance of power system. Preeminence of national interest: authorities must constantly work to guard and advance state interests- looking out for number one. It must be lead by political objectives: types of war, limited or small- scale vs total war. Inter- state vs. internal/civil war: status quo, hegemonic, and revisionist war. Is the final arbiter of disputes. We do it because we are defending ourselves. Otherwise pills countries into war that don"t need to be in the war: 2.