There is no question that the Iraq War upended the balance of power in the Middle East, but the war has had a similarly profound effect on American politics as well. It left sizeable swaths of the American population on both the left and the right questioning not only whether the United States should conduct armed nation-building in the future, but to what degree, if any, the United States should be militarily involved abroad at all.
Director, Strategy and Doctrine Program, RAND Project AIR FORCE
Source: The RAND Blog