http://www.nytimes.com/interactive/2014/10/14/world/middleeast/us-casualties-of-iraq-chemical-weapons.html?_r=1
http://www.foxnews.com/world/2014/10/17/dragon-egg-marines-who-guarded-saddam-mysterious-bunker-fear-weapons-unleashed/
I say they never left. And that of course, means, Yes, they were there all along.