If Argentina did for some reason invade, the Brits cannot bomb Argentina. They have no bombers ,,, period. Their only strike aircraft has a useful range of about 875 miles. Falklands to Buenos Aries is about 1100.
The Harriers are gone. The Vulcans are gone. The carriers of the British Cold War ear Navy are gone. About all the Brits could do is interdict them with subs. But they cannot project combat power.
Their bigger problem is moral rot. This is the Royal Navy that had a boarding party captured by the Iranians ***within sight*** of a RN destroyer. That would have been utterly unimaginable in the past. Nobody would have even dared.
RN attack subs are equipped with Tomahawk cruise missiles. Not enough to do major damage, but they could be used in a Doolittle style raid against a couple/few targets (like powerplants) that would send a message.
The RAF is still the biggest in Europe and second in NATO, second only to you. The Army still punches well above its weight.