What Marines did in the Caribbean between 1991 and 1996 was both new and old. It was new because humanitarian operations were different from combat in Vietnam or Southwest Asia. It was also new For many because it was "joint," Marines were integrated into joint task forces, especially when they were called on to care for Haitian and Cuban migrants at Guantanamo Bay. But it was also old and familiar. Generations of Marines have deployed to the Caribbean in one role or another. Although they would not have recognized the words, Marines in Haiti, Dominican Republic, or Panama knew the notions of "military operations other than war "and" low intensity conflict" earlier in the 20th century. It is no accident some of the Marines who went to the Caribbean in the 1990s took with them a copy of The Small Wars Manual, a Marine Corps classic about unusual challenges on foreign shores written between the two world wars by writers with fresh memories of earlier operations in many of the same places. If there was one lesson in the Caribbean, it was that traditional Marine Corps virtues-initiative, discipline, and flexibility-were still as useful and applicable in the final years of the last century as they had always been. Humanitarian operations did not lack intensity. The challenges some of the Marines in this story faced were not combat, but on some days they came close, as thin green lines of Marines confronted crowds of angry and violent migrants at Guantanamo and in Panama, When the Marines of Special Purpose Marine Air-Ground Task Force occupied the northern provinces of Haiti in September 1994, they entered an unusual environment that, at least at first, was not war and not peace. They had to deal with large and usually friendly crowds, as well as a hostile police force and military that disappeared from the scene only after a brief but intense firefight that left a number of Haitian policemen dead. If there are any overall lessons, they are that the same Marine rifleman has to be ready for combat and military operations other than war, and that it is the leaders of small units, squads, and platoons who often determine the outcome in ambiguous situations.