At the risk of criminal oversimplification, one could look at the last seven decades of U.S. foreign policy as a story of two competing ideas.
One, which flowered after the fall of the Soviet Union, is liberalism. Among its tenets is that America benefits if it spreads its values across the globe and is willing to use its economic and military power where liberty, sovereignty and universal rights are threatened. This school brought us the good (Ukraine, at least for now), the bad (the 2003 Iraq invasion) and the ugly (Kosovo in the late 1990s). There are various factions — liberals, interventionists, neoconservatives, etc. — but the idea is that the U.S. does well by doing good.