The U.S. could have stopped ISIS at any point during its initial invasion of Iraq, but didn't. Now a protracted ground war would be necessary to remove them, and it's likely that another million brown people in the middle east would die as a result off intervention. There isn't enough wisdom in the US government to force the end result of off intervention, so we should not intervene. If we had been wiser following September 11 then this mess could have been entirely avoided. Also, this war has gone on too long. The more money we spend on war, the less free the average American is. Also, these wars are constantly used to justify bills like ndaa and the patriot act, which directly deprive U.S.citizens of constitutionally protected rights. The terrorists don't hate us for our freedom, they hate us because we killed their dad, mom, sister, daughter...