A good example is the U.S. invasion of Grenada—Operation Urgent Fury, as it was called by the Reagan administration—launched exactly 30 years ago this week, on Oct. 25, 1983. Grenada made an unlikely target of U.S. military might. Its main product was not oil but nutmeg. Its naval fleet consisted of about 10 fishing trawlers. Grenada’s population of 110,000 was smaller than Peoria, Illinois. At the time of the invasion, there was not a single stoplight in the entire country. So what put Grenada in the crosshairs of the Reagan administration?

In 1979, the socialist New Jewel Movement had overthrown the corrupt and unpopular dictator Eric Gairy in an almost bloodless coup.