In the 70's, Argentina claimed 3 Chilean island at the eastern end of the Canal Beagle. Negociations with Chile did not succeed and hard liners in Argentina's junta decided to take the islands by force. At this time, Argentina had stronger armed forces than Chile and expected a quick and total victory.
The details of Argentina's battle plan are not easy to fix (almost everything is in Spanish, which I don't speak, and there are several versions) but roughly, Argentina's naval infantry was to take control of both contested islands (Picton, Nuva and Lennox) as well as another archipelagos (Wollaston, Freycinet, Herschel and Horn islands) by amphibious and / or airmobile assaut. The next morning, the Air Force would attack air bases in Chile (and hopefully, destroy the few enemy combat aircrafts on the ground), while the army would launch severall offensives across the Andes to capture key points in Chile (Santiago, Valparaiso, ...). The navy was to ambush the Chilean fleet attempting the retake the lost island and sink it.
Fortunately for both countries, bad weather delayed the Argentinean landing on the islands, and gave enough time to pope John Paul II to impose a mediation. War was avoided by a narrow margin (some sources say that there were actually a few shots exchanged) and both countries escaped a war in which they had probably nothing to gain but a lot to loose.