OK, I'll be serious. We didn't have to be involved, because we could have done what we had the chance to do seven years ago: remove the worst of the terrorists from Iraq via the surge, helped the Kurds gain the autonomy they have wanted for at least 100 years for which they would have remained our forceful allies, surrounded Iran on all sides (Iraq/Turkey on the west, "stans" on the north, Afghanistan on the east, Sixth Fleet to the south) and contained her while supporting the later 2009 uprising--and drill-baby-drilled in north America, complete with pipelines, trains, and tankers, to make the Middle East and Russian fossil fuels less and less relevant.
It is because we didn't do any of the above after January 2009, however, that we are stuck having to clean up the mess now--and to be honest, we won't be really cleaning up the mess until at least 2017, and not even then if Hillary! replaces the present occupant of the Oval Office.
/bingo