The fear driving the plan had a name: Exocet. Argentina's five French-built Super Étendard fighters, flying from Río Grande, carried air-launched Exocet missiles that had already proven they could sink British warships. The loss of those ships sent a shock through the task force and the war cabinet in London. Argentina was believed to have only a handful of the missiles left, and every one was a threat to the fleet steaming toward the Falklands. If the Super Étendards and their remaining Exocets could be destroyed on the ground, the danger to the British ships would largely vanish. The question was how to reach an airbase fifteen hundred kilometers from the fighting, on the Argentine mainland itself.

Brigadier Peter de la Billière, the SAS director, looked to a famous precedent: Israel's 1976 raid on Entebbe, a long-range strike landed boldly on a hostile runway. His version called for around 55 troopers of B Squadron, flown in two Lockheed C-130 Hercules that would touch down directly on the Río Grande airfield under cover of night. The commandos would destroy the aircraft and the pilots, then attempt to escape, by helicopter, by sea, or by seizing whatever vehicles they could and making a desperate dash for the Chilean border roughly eighty kilometers to the west. The base, however, was no soft target. By late May it was crammed with more than 1,200 men, three times its capacity, ringed with Bofors and Oerlikon anti-aircraft guns and defended by Argentine Marine battalions.

First, someone had to scout the ground. On the night of 17 May, a reconnaissance mission codenamed Operation Plum Duff sent an eight-man SAS team toward Tierra del Fuego aboard a stripped-down Royal Navy Sea King helicopter, launched from HMS Invincible. The flight went wrong almost immediately. The aircraft strayed near an offshore gas rig and had to detour; after four hours in the air, dense fog dropped visibility to under a mile. Near the planned drop-off, the pilot and the patrol commander disagreed sharply on where they even were, and the commander, convinced an Argentine patrol had spotted them, demanded to be set down at the Chilean border instead. The Sea King's crew, unable to return, flew on into Chile and destroyed the helicopter. The reconnaissance, the essential first step, had collapsed.

Operation Mikado was never launched. The reconnaissance failure, the obvious strength of the defenses, and the near-certainty that the lumbering Hercules would be detected long before they touched down all weighed against it. The British government later acknowledged outright that the operation would very likely have failed. The Argentines, it turned out, were braced for a special-forces attack, though their commanders said afterward they never imagined the British would try to land a Hercules directly on their runways. The mission survives now as one of the great what-ifs of the Falklands War: a plan so audacious and so dangerous that the men who studied it gave it the name of the fate they expected, and a quiet relief, on both sides, that it stayed on paper.