I'd expect the US to announce that they're going to go put boots on the ground in Yemen before they do so. If they're going to do it unannounced then it'll be some JSOC psychos not the marines. Not a "massive" invasion.

Aren’t you glad you updated your post title now, @[email protected]? :P

Yemeni sources indicate that the departure of USS Dwight D. Eisenhower and USS Gravely from the Red Sea is part of the preparations for the coming assault.