In 1982, there was only a tiny garrison of some 40 marines based in the Falklands, hence they were relatively easily overrun. Now, according to our military top brass, we are perfectly capable of handling any attack Argentina could reasonably mount, given that they are, for example, still flying the same aircraft they used back then.
In addition, of course, we could even nuke Buenos Aires from a submarine, if we felt like it, or - more reasonably - pound their attacking soldiers from patrolling surface ships.
The reason the islanders are so determined to remain British is the fact that so many of their forebears actually WERE shepherds from some of our "remoter Scottish islands"!