On April 27, 1965, when the war threatened to engulf the city’s western sector where most of the foreign diplomatic offices were located, U.S. President Lyndon B. Johnson (who had succeeded President Kennedy after the latter’s assassination), ordered U.S. naval forces in the Caribbean to evacuate U.S. citizens and other willing foreign nationals from Santo Domingo. Hundreds of foreign civilians and diplomatic personnel gathered at Hotel Embajador in the city’s western sector were transported by helicopter to U.S. Navy ships at Haina Port, and then evacuated out of the country. During the war, some 6,500 foreign nationals from 46 countries were evacuated.
(Taken from Dominican Republic Civil War – Wars of the 20th Century – The Western Hemisphere – Volume 7)
William Tapley Bennett, the U.S. Ambassador to the Dominican Republic, believed that a Constitutionalist victory in the war would lead to Castroists turning the country into a communist state. In an urgent cable to Washington, D.C., he asked President Johnson to intervene so as “to restore order beyond a mere protection of lives. If the present Loyalist efforts fail, the power will go to groups whose aims are identified with those of the Communist Party. We might have to intervene to prevent another Cuba.”
On April 29, 1965, some 400 U.S. Marines were landed to proceed to and protect the U.S. Embassy. President Johnson also purposed the operation to initiate U.S. Army presence and buoy up support for the flagging Loyalist forces. The U.S. Armed Forces then made preparations to land more troops through San Isidro Airfield, located east of Santo Domingo.
First, however, the United States needed to gain permission from the OAS, whose member-countries were already condemning the U.S. operations. Then in a session held on April 30, 1965, the OAS lambasted the U.S. government, declaring that American operations in the Dominican Republic were a flagrant violation of OAS regulations that forbid any OAS member-country from interfering in the internal affairs of another OAS member-country. At the same time, however, the OAS was concerned about the Dominican Republic falling to communism. Ultimately, a compromise agreement was reached: the U.S. Army could proceed with its operations until such time that an OAS force arrived to take over and carry out peacekeeping duties. The United States then would scale back military operations.
In early May 1965, large numbers of U.S. soldiers were landed at San Isidro Airfield; the U.S. presence eventually would peak at 22,000 troops on May 17. Assisted by their Dominican Loyalist allies, the Americans secured San Isidro town located east of Duarte Bridge, at the eastern entrance to Santo Domingo. Then in a lightning operation that lasted just over one hour, in the early morning of May 3, U.S. forces seized control of a 25-kimeter strip extending from San Isidro to the U.S. Embassy in Santo Domingo, which they declared a neutral zone called the “Line of Control” (LOC). Subsequently, the LOC was extended further west to the city’s diplomatic section and Hotel Embajador.
The LOC allowed U.S. forces east and west of the city to link up; more important, it physically separated Constitutionalist and Loyalist forces. The U.S. Army quickly consolidated its hold on the LOC, preventing either armed side from crossing and thus effectively putting an end to the fighting.
President Johnson had conceived the U.S. intervention as a means to force the two sides to the negotiation table. He therefore stopped active support for the Loyalists and ordered the U.S. Army to carry out a “hearts and minds” campaign to the general population, i.e. distributing food and clothing and providing medical services to win over public support to the foreign presence. Began in Santo Domingo, by May 1966, these civic action programs were being expanded to rural areas.
The LOC also sealed in the Constitutionalists within the confines of Ciudad Nueva. There, on May 3, 1965, former legislators from President Bosch’s 1963 Congress proclaimed Colonel Caamaño as President of the Dominican Republic. Not to be outdone, four days later on May 7, the Loyalists, with U.S. tacit approval, declared General Antonio Imbert as the country’s President under the “Government of National Reconciliation”. (General Imbert previously had taken part in the assassination of the dictator Trujillo). The LOC also allowed Loyalist forces to eliminate Constitutionalist pockets of resistance outside Ciudad Nueva; the Loyalist capture of Radio Santo Domingo dealt a major blow to the Constitutionalists, as broadcasts from the radio station had generated massive public support for the rebellion early in the war, bringing about combat success, and were keeping the flagging hope of a Constitutionalist political victory alive even after the U.S. intervention.
Map 36: Dominican Republic Civil War.
On May 5, 1965, the two sides agreed to a ceasefire, which was mediated by the United States and OAS. The next day, the OAS established a peacekeeping force, the Inter-American Peace Force (IAPF), which was organized from military and police units from Brazil, Honduras, Paraguay, Nicaragua, Costa Rica, and El Salvador, and arrived in the Dominican Republic on May 23. Security functions were turned over to the IAPF, allowing the United States to withdraw most of its troops.
By early May 1965, large-scale fighting had ended, although small bands of Constitutionalists sometimes skirmished with IAPF peacekeepers. On June 14, 1965, Constitutionalists launched a major attack on the LOC, but were thrown back. The IAPF then counter-attacked and seized control of a section of Ciudad Nueva, which it eventually returned to the Constitutionalists.
Peace negotiations between Constitutionalists and Loyalists took place, which led to an agreement called the “Act of Dominican Reconciliation and the Institutional Act”, signed on August 31, 1965. In the agreement, the two sides agreed to stop their claim to exclusive political authority (causing them to dissolve their respective “governments”), respect the truce, and work together to organize a provisional government that would lead the country until free elections were held. On September 3, 1965, a provisional government was formed and headed by Héctor García-Godoy, a former Foreign Minister in the Bosch regime, to serve as interim President.