Like which wars??
WWI where Wilson did his damndest to provoke the Central Powers, who didn't bite, and Wilson intervened anyways??
WWII, where FDR deliberately provoked the Japanese??
Korea, where Truman intervened by executive fiat??
'Nam, where LBJ lied about the Golf of Tonkin incident??
WW1 occurred in part because the US prior to the war refused to be involved in European affairs.
WW2 happened because Europe refused to do anything about Hitler. The US again refused to be involved in European affairs.
Korea occurred because the Soviet Union armed, trained and supplied the North Koreans and then ordered them to invade to test the will of the West. The US was involved because we had treaty obligations and we fared poorly in the first months because we let our military dwindle to nothing.
Vietnam was another test between the Soviets and the West. And in the end on that one the Soviets got what they wanted. Why? Because the liberals refused to honor our treaties.
Grenada occurred because the Soviets and Cuba believed the US was a paper tiger. Panama occurred because the US let Noriega think he could dictate to the US anything he wanted.
Kuwait Occurred because an IDIOTIC Ambassador let Saddam believe the US would do nothing if he invaded Kuwait.