Overview Last updated: December, 2013
Cuba is not known to have nuclear, chemical, or biological weapons programs, and is a participant in many of the major nonproliferation treaties and regimes.
Fidel Castro spearheaded a revolution that was successful in removing President Fulgencio Batista from power in 1958. Relations between Washington and Havana deteriorated rapidly soon thereafter, and within a few years the United States broke diplomatic relations (January 1961), was influential in having Cuba thrown out of the Organization of American States (January 1962), and imposed a total trade embargo on Cuba (February 1962). Tensions between the United States and Cuba peaked during the so-called "Cuban Missile Crisis" of October 1962, but have since settled at a lower, albeit still high, level. Low level diplomatic relations were resumed in 1977 when the United States and Cuba opened “interest sections” in Havana and New York, respectively.
As a counterweight to U.S. power, the Cuban government entered into a series of agreements with the Soviet Union that led the two countries to establish close economic and political ties, including military and defense arrangements. Relations between Cuba and Russia became strained after the dissolution of the Soviet Union, which led to the cessation of all assistance from that country and, subsequently, Russia. In recent years however, the two countries have worked to renew their former alliance. While initial agreements focused on the civilian sphere , current proposals include expanded military cooperation and the potential establishment of a resupply base for the Russian navy in Cuba. 
Under Castro, Cuba became a highly militarized society. Massive Soviet military assistance enabled Cuba to upgrade and increase its military capabilities, which in turn were used to send military units abroad. As of July 2013, Cuba’s future course remains uncertain. This period of uncertainty began in August 2006, when Fidel Castro, battling illness, ceded power to his brother Raul Castro. The change of power was made permanent in February 2008 when Castro announced that he would not accept another term as president, which led to Cuba’s Parliament electing Raul Castro as the new president on 24 February 2008. It is unclear how much influence Fidel Castro continues to have over policy making in Cuba and thus how much real power Raul Castro possesses.
Cuba also maintains ties with both Iran and North Korea. Cuban officials have voiced support for Iran's nuclear program, and have sought to increase economic ties between the two countries despite Western sanctions against Tehran. 
While Fidel Castro has expressed concerns about North Korea's nuclear program in the past, recent events suggest that Cuba may be helping Pyongyang to circumvent UN sanctions that limit the country's ability to import and export weaponry. In July 2013, the North Korean armed forces' chief of staff met with Cuban military leaders and president Raúl Castro.  Shortly thereafter, Panamanian authorities intercepted a North Korean ship travelling from Cuba carrying 240 metric tons of military equipment, including one S-75M Volga (NATO: SA-2 Guideline) and one S-125 Pechora (NATO: SA-3 Goa) anti-aircraft missile complex; nine missiles in parts and spares; two MiG-21bis fighter jets; and 15 motors for the MiGs. The Cuban Foreign Ministry issued a statement claiming the equipment was being sent to North Korea for upgrades, and was then to be returned to Cuba. 
Cuba does not possess nuclear weapons, and there are no credible reports of Cuban efforts to acquire these weapons. In 2002, Havana acceded to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), ratified the Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean (Treaty of Tlatelolco), and deposited an Additional Protocol with the IAEA.
In the 1980s, Cuba raised international safety and proliferation concerns with the construction of a nuclear power plant in the south central province of Cienfuegos, near Juragua, about 180 miles south of Key West, Florida. The project started in 1976 when the Soviet Union and Cuba signed a formal agreement to build two 440-megawatt pressurized water reactors to provide electricity for Cuba's growing energy needs. Construction started only in 1983 and was suspended in 1992 due to the termination of Soviet financial aid to Cuba after the collapse of the USSR. Since 1995, attempts by Cuba and Russia to obtain international financing to finish the project revived U.S. concerns about its safety and proliferation effects.  Cuba had not signed the NPT or the Tlatelolco Treaty at that time and there were allegations by Cuban nuclear power officials about existing problems that could affect the safe operation of the reactors.  Cuba and Russia failed to find international support for the project and on 17 January 1997, then Cuban President Fidel Castro announced its "indefinite postponement". Russia retained interest in completing the nuclear plant until December 2000 when President Vladimir V. Putin visited Cuba and was told by President Castro that Cuba was no longer interested in completing the twin 440-megawatt reactor plant. 
While both public and private persons have with some frequency alleged that Cuba has supported a secret biological warfare (BW) program, no convincing proof of the existence of such a program has been presented. Cuba signed the Biological and Toxin Convention (BTWC) in 1972 and ratified it in 1976.
Since approximately 1981, Cuba has developed a powerful biotechnology capability, which is possibly the most advanced among developing countries. Certainly, Cuba’s biotechnological and medical industries are the largest and most sophisticated in Latin America, as demonstrated by its large-scale production of pharmaceuticals and vaccines. This capability is being used to develop and produce products for exports, and the income from these exports might be larger than all other income-generating endeavors, with the exception of sugar and tourism.
Cuba is not suspected of having acquired or produced long-range ballistic missiles.
In October 1962, Cuba was the stage for the most dangerous confrontation between the United States and the Soviet Union during the Cold War. In May 1962, Soviet Premier Nikita S. Khrushchev secretly began deploying R-12 Dvina (GRAU: 8K63; NATO: SS-4 Sandal) medium range ballistic missiles (MRBM) to Cuba as a means to counter the U.S. lead in strategic missiles and protect Cuba from an U.S.-sponsored invasion. Presented with photographic evidence of missile installations under construction, President John Kennedy chose naval blockade as the course of action against Soviet ships. The strategy proved to be successful and on 28 October, Khrushchev announced that he would dismantle the installations, expressing his trust that the United States would not invade Cuba.  Unknown to the United States at the time, Khrushchev had also transferred almost 100 tactical nuclear weapons to Cuba, including 80 nuclear-armed Front Cruise Missiles (FKR-1; NATO: SSC-2A); 12 nuclear warheads on Luna (GRAU: 2K6; NATO: FROG-3/5) short-range artillery rockets; and 6 nuclear bombs for IL-28 bombers. These weapons were also removed in the wake of the crisis, even though they were not a part of the negotiations.  The Soviet Union intended to deploy R-14 Chusovaya (GRAU: 8K65; NATO: SS-5 Skean) intermediate range ballistic missiles (IRBM) on the island; however, the U.S. blockade prevented the missiles from reaching Cuba.
 Michael Schwirtz, "Cuban ties to Russia strengthen with visit; Difficulties with U.S. have driven alliance," International Herald Tribune, 31 January 2009.
 Henry Meyer and Anatoly Temkin, "Russia Seeks Naval Bases in Cold War Allies Cuba, Vietnam," Bloomberg News, 27 July 2012; "Russia, Cuba have good potential for expanding military cooperation - RF Chief of Staff," ITAR-TASS, 20 April 2013.
 "Cuba backs Iran's right to develop nuclear technology for peaceful purposes," Press TV (Iranian State News Channel) via BBC Worldwide Monitoring, 12 December 2012.
 "Raul Castro Greets North Korean Military Delegation," ACN (Cuban News Agency), 2 July 2013.
 James Hardy, "Cuba confirms ownership of materiel found on North Korean ship," IHS Jane's 360, 16 July 2013; "Declaración del Ministerio de Relaciones Exteriores," ACN (Cuban News Agency), 16 July 2013.
 Scott Parrish, "Russia, Cuba, and the Juragua Nuclear Plant," NTI, May 1997, www.nti.org.
 "Nuclear Safety: Concerns with the Nuclear Power Reactors in Cuba," GAO/RCED-92-262, 24 September 1992, http://archive.gao.gov.
 Patrick E. Tyler, "Cuba and Russia Abandon Nuclear Plant, an Unfinished Vestige of the Soviet Era," New York Times, 18 December 2000, www.lexisnexis.com.
 "Cold War: Cuban Missile Crisis," Revelations from Russian Archives, Library of Congress, www.loc.gov; Laurence Chang and Peter Kornbluh, "The Cuban Missile Crisis, 1962," The National Security Archive, George Washington University, www.gwu.edu and "Cordon of Steel The U.S. Navy and the Cuban Missile Crisis," Department of the Navy, Naval Historic Center, www.history.navy.mil.
 Svetlana Savranskaya, "Cuba Almost Became a Nuclear Power in 1962," Foreign Policy, 10 October 2012.
This material is produced independently for NTI by the James Martin Center for Nonproliferation Studies at the Monterey Institute of International Studies and does not necessarily reflect the opinions of and has not been independently verified by NTI or its directors, officers, employees, or agents.
Get the Facts on Cuba
- 1963 Cuban Missile Crisis a key Cold War confrontation between the United States and the Soviet Union
- Possesses a well-developed biotechnology sector with dual-use capabilities
- No evidence to suggest Cuba possesses or is pursuing ballistic missiles