If he follows his usual modus operandi on Foreign Policy and Military matters, Obama will study the issue for about 90 days, gathering input, after which he will issue a statement. Or not, as the issues at-hand may be overcome by events (he would hope). ...all the while whispering to the Brits "we're on your side".

It's my guess that he won't try to resurrect Monroe; rather he'll most likely kick it to the UN. Meanwhile, the boys in Florida (home of CentCom) will have already dusted off the '82 OpPlans for updating, and have the Navy, MilAirliftCmd & a brigade of 82d Airborne on heightened alert (quietly).