These cases are not at all similar and should be examined more closely. In Syria U.S. bombing stopped a genocide being conducted by ISIS on the Yazidi population, usually seen as a worthwhile effort. In Iraq U.S. air power stopped Saddam's genocidal campaign against Iraqi Kurds and protected their nascent nation from his murderous desires for years. Bush threw away much good we had done with his idiotic invasion, but for many years Kurds were not gassed and strafed from the sky and actually managed to build a fairly democratic state while under protection. It bears remembering that most of the violence and death in Iraq and Afghanistan was committed by Iraqis and Afghanis, following ancient religious and ethnic enmities, and while we bear the responsibility for removing the despotic rule that tamped down the conflict they could always have chosen to go a different direction, to not conduct civil war against each other.