Without a Status of Forces Agreement, the only thing they can do, outside the US embassy, is to give classes.
And is 300+ the 300 already there much different than the 3,000 that Obama said would be the max under any SoF Agreement?
It would be prudent to use this crisis to negotiate a new SOFA. But neither the Sunnis nor Shia want to cede operational latitude to American forces. I.e., allow US forces to operate autonomously in Iraq, with legal immunity. Reason #1 for this IMO is each thinks they’ll prevail and be in control of the country so neither wants a potential referee limiting their efforts to gain and maintain control. Indicator neither intends to play fair with anyone else. These people are Old School. Very Old School.
In hindsight I’d say sovereignty should have been put off to 2012 then dictate that we stay behind at our bases in Mosul, Balad, Victory-BIAP, and Basrah.