Sorry, but "just cut our losses" isn't acceptable to me when people are being murdered. This is the Nazi murder of Jews/etc of our time and it's everyone's obligation to handle it better.
Bush caused most of this current ISIS problem by lying about WMDs. At that point, we're the bad guys invading on a lie. It made us afraid of and hostile towards the Iraqis which caused the Abu Ghraib treatment, etc. He didn't make the terrorists but he provided them with their recruiting propaganda, made an ideal nest, and let them crawl in. It sucks, but we've got an uphill slog because we elected someone who was fine with murdering people on a lie.