This document is a strategy research project analyzing key international relations concepts and the Bush Doctrine. It provides historical context on the evolution of US foreign policy from 1776 through the post-9/11 era. It discusses concepts like exceptionalism, unilateralism, preemption, and hegemonic stability. It examines how US strategy shifted from isolationism to engagement following World War II and the Cold War. It analyzes how the Bush Doctrine articulated in the 2002 National Security Strategy expanded the use of preemption in response to new threats like terrorism.