On 6 September 1976, an aircraft appears out of the clouds near the Japanese city of Hakodate, on the northern island of Hokkaido. It’s a twin-engined jet, but not the kind of short-haul airliner Hakodate is used to seeing. This huge, grey hulk sports the red stars of the Soviet Union. No-one in the West has ever seen one before. The jet lands on Hakodate’s concrete-and-asphalt runway. The runway, it turns out, is not long enough. The jet ploughs through hundreds of feet of earth before it finally comes to rest at the far end of the airport. The pilot...