One must study the entire eighteen months of American participation in the Dominican intervention to answer such controversial questions as whether U.S. policy was truly neutral. American policy changed during the period from favoring a rightist junta, to a neutral policy, to finally favoring a very liberal, provisional government. An important factor in this shift was the changing military situation. Early in the crisis, when it appeared the rebels might win and there were few American troops in Santo Domingo, U.S. policy favored the Wessin y Wessin junta. American military officials supplied the junta with communications equipment, military assistance officers and attachés conducted joint planning with the San Isidro generals, and the joint task force furnished the junta with liaison officers. With the American troop buildup and the resulting decreased communist threat U.S. policy became increasingly neutral. After completion of the buildup and containment of the rebels in downtown Santo Domingo, American policy shifted to restraining the Imbert forces from attacking the insurgents and persuading the Imbert junta to accept a left-leaning provisional government. Not only had American foreign policy requirements limited U.S. military operations, but military operations had allowed foreign policy to shift as the military situation improved.
Complexity also characterized the Dominican factional dispute, American military operations in the Dominican Republic, and the activities of groups associated with the search for a cease-fire and negotiated peace. The crisis began with a coup that overthrew the existing government, then became a limited war between two factions, both claiming to be the legitimate Dominican government. Then the provisional government formed in September 1965, exiled the leaders of the contending factions and served as an interim government until the formation of a constitutional government in July of 1966. American military operations likewise changed from a relatively simple rescue of endangered Americans by five hundred marines into a preventive intervention of over 23,000 U.S. troops and airmen. This force then rapidly decreased to one-third its original size as U.S. forces became part of an inter-American peace force in the Dominican Republic. Also, the United Nations, OAS, and the United States sent representatives to the Dominican Republic to aid the papal nuncio