In 1982, the United Kingdom and Argentina fought a major war over the Falkland Islands. And yes, it was a major war. The British lost two destroyers, a landing ship, a merchant vessel, and two frigates. The Argentinean Navy lost a cruiser.
This doesn’t count the land or air battles as well. But Argentina hasn’t given up hope of taking back what they call the Malvinas. What would happen if they tried to take the islands today?
Both the Royal Navy and the Argentinean Navy have declined greatly, according to the “16th Edition of Combat Fleets of the World.” In 1982, the British had two carriers they sent down to the south Atlantic. Today, the UK only has one — the HMS Ocean — and that ship cannot really operate the F-35 fighters that the Brits have bought, and their Harriers are long retired.