If the UK hadn't acted decisively, then there would have been no end to it. Think about the Soviets and Spanish.
It was a bullying act by a junta that had got used to getting its way at home, and thought it could pull the same trick on 'sick man Britain'. But it didn't come off, and the bully was confronted and beaten on the islands.. and as a result at home too.
I'm no fan of Thatcher, if she'd got her way earlier we probably wouldn't have had a task force to send South, but when presented with the crisis she was up to the job. The Argies were the mob and they needed to be stopped. The UK enforced law and order.