In 1962, the Soviet Union and Cuba agreed to have Soviet nuclear missiles deployed on the island nation, just 90 miles from the United States. They were two sovereign states, so no one had the right to prevent them from doing this – if you follow the West’s prevailing arguments in the current Ukraine crisis.
But U.S. President John F. Kennedy saw a security threat. By threatening military force, he compelled the Soviet Union to dismantle missile sites and imposed tough sanctions on Cuba.
According to today’s arguments on Ukraine, the U.S.’s intervention in Cuba clearly violated international law. But most of the world appreciated what President Kennedy did at the time. The United States had already violated international law a year earlier, by supporting exiled Cubans in their failed Bay of Pigs invasion to overthrow Fidel Castro’s government.