It will be interesting to see just who else jumps on board at the UN. There is a large Latin American backing and the UN has always been championed by Western 'Allied' governments as having the ultimate say so (remember Blair was insistent that we sought UN backing prior to liberating Iraq from the tyranny of Saddam!)
It would be very hypocritical of us now to stand in the way of the UN should they issue a dictate that says we must talk to Argentina on the issue of sovereignty!
I'm playing Devil's advocate here; but if China were to jump on board, what would we do then? The Falklands is also a strategic base for the UK's future exploration of the Antarctic's possible reserves. If China were to do a US/Taiwan pact with Argentina on the basis they could use the Falklands as a stepping stone to the contested riches of the Antarctic then who knows where this could lead?
Argentina/Brazil/Venezuela know that we are fully committed to Afghan and our focus is elsewhere currently. Could this be the UK's economic and military 'Black Swan' that people were not quite expecting as they merrily slashed the Navy and RAF to pieces? Time will tell......(and yes I have been there; 3 times!)