airpolice,
A few things wrong with your thinking:
You say: "I'm not saying they are coming before Easter, but if they did, we're in no position to stop them."
This is not true. The Typhoons would be more than a match for anythig the Argentines could put up against them (they have not recieved any new combat aircraft since before 1982). I know quantity has a quality all its own, but the FAA wouldn't even get close. They know this too which is probably why they raised such a stink when they were deployed. Also, their navy would not put to sea as they have no way to counter the UK's nuclear submarines.
With no air or sea dominance (or even parity) they wouldn't be so stupid as to try and invade.
Secondly, you say: " Since the US didn't help us the last time, it's fair to expect them not to help us next time."
Again, you're wrong. They did help by allowing us to dip into NATO stocks of the latest Sidewinder missile which allowed for shots other than directly behind. This missile was the main reason for the Sea Harrier's success. Satellite imagery was also provided and they offered us the use of an aircraft carrier but this was turned down for political reasons. It is fair to assume that such 'behind the scenes' help would again be offered if needed.
Again; "Losing one Typhoon would be a huge hole in the air defence cover, but losing one Hawk out of maybe four or five times as many Hawks as Typhoons would be less of an issue." The point is that the FAA wouldn't get close enough to take down any Typhoons. If it were Hawks they were up against it would be a very different story.