An excellent analysis of the hubris that permeates American foreign policy, by Doug Bandow at theamericanconservative.com:
Whichever party wins elections, the foreign policy establishment will find a war to get involved in and a means to justify it.

Since the end of the Cold War there have been few external constraints on U.S. foreign policy. The Soviet Union’s collapse left America as the unipower. “What we say goes,” declared President George H.W. Bush. Washington’s foreign policy establishment, later termed “the Blob,” saw an opportunity to transform the world.
The 1990s featured military interventions in the Balkans, Somalia, Haiti, Panama, and Iraq. All were unnecessary wars of choice, though Panama was close geographically and hosted the important Panama Canal. Iraq’s conquest of Kuwait unsettled the Mideast, but less than had other conflicts, such as the eight-year Iran-Iraq War. Overall, these interventions had only modest consequences for the U.S. All were limited, imposed minimal direct costs, and came to an expeditious end. No one spoke of “endless wars.”
Much worse, he invaded Iraq—which had no WMDs, as he had falsely claimed—triggering a devastating sectarian war. Thousands of allied troops were killed; tens of thousands were injured; hundreds of thousands of Iraqis were killed; millions were displaced; trillions of dollars were wasted. Religious cleansing destroyed the indigenous Christian community and was followed by devastating attacks on other faith minorities, such as the Yazidis. Al-Qaeda in Iraq was loosed, mutating into the even more destructive Islamic State.