After decades of disagreement, Egypt nationalized and seized control of the Suez Canal in July 1956, sinking ships to plug the shipping route between the Mediterranean Sea and the Red Sea. The canal had been regulated and operated under an international system since the Convention of Constantinople of 1888. The British considered the canal crucial, its closure an economic threat. France backed its ally Israel, whose cargo ships traversing the canal had been routinely searched and seized by Egypt. Britain, France and Israel attacked Egypt at the end of October. Egypt appealed to its ally, the Soviet Union, whose response was to threaten to use nuclear weapons unless the attacks stopped. As allies on both sides lined up to lend support and an international conflagration loomed, a Ca...