From John Walker's Reading List comes a story of the Falklands War. When the Argentines occupied the Falklands, the British had a problem: how do we project force halfway around the world with the men and equipment we have on hand right now? They dispatched the Royal Navy, but it would take two weeks for the task force to arrive: too late to do any good. Some Avro Vulcan bombers were available, but they were completely wrong for the mission. Dedicated for nuclear strikes at short range, they had no equipment for mid-flight refueling, no hardware for dropping conventional bombs, and the wrong navigational equipment for flying over the ocean.
Nonetheless, the Brits retrofitted the planes and flew them to the Falklands to put a single crater in the island's airfield. This made the airstrip too short for the Argentine jets, but long enough for a C-130. A masterpiece of improvisation, and in retrospect, a crucial mission for the outcome of the war.
h/t John Walker