Having a meaningful ground force in the region means that we would have been able to respond in kind to whatever sectarian group rose up to threaten stability in the region, supplemented by our Iraqi Allies.  Under our leadership there would have been a lot less of just abandoning the vehicles that we paid for and going home.  We also would have had the pieces in place to make a RED LINE against using WMD a meaningful ultimatum instead of a political show and that could have influenced what happened in Syria. 

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