Cuba is a totalitarian state controlled by Fidel Castro, who is chief of state, head of government, First Secretary of the PCC, and commander in chief of the armed forces. Castro seeks to control most aspects of Cuban life through the Communist Party and its affiliated mass organizations, the government bureaucracy, and the state security apparatus. In March 2003, Castro announced his intention to remain in power for life. The Ministry of Interior is the principal organ of state security and control.

According to the Soviet-style Cuban constitution of 1976, the National Assembly of People's Power, and its Council of State when the body is not in session, has supreme authority in the Cuban system. Since the National Assembly meets only twice a year for a few days each time, the 31-member Council of State wields power. The Council of Ministers, through its 9-member administrator committee, handles the administration of the economy, which is state-controlled except for a tiny and shriveling open-market sector. Fidel Castro is President of the Council of State and Council of Ministers and his brother Raul serves as First Vice President of both bodies as well as Minister of Defense.

The Communist Party is constitutionally recognized as Cuba's only legal political party. The party monopolizes all government positions, including judicial offices. Though not a formal requirement, party membership is a de facto prerequisite for high-level official positions and professional advancement in most areas, although non-party members are rarely allowed to serve in the National Assembly. The Communist Party or one of its front organizations approves candidates for any elected office. Citizens do not have the right to change their government. In March 2003, the government carried out one of the most brutal crackdowns on peaceful opposition in the history of Cuba when it arrested 75 human rights activists, independent journalists and opposition figures on various charges, including aiding a foreign power and violating national security laws. Authorities subjected the detainees to summary trials and sentenced them to prison terms ranging from 6 to 28 years. Amnesty International identified all 75 as "prisoners of conscience." The European Union (EU) condemned their arrests and in June, it announced its decision to implement the following actions: limit bilateral high-level governmental visits, reduce the profile of member states' participation in cultural events, and invite Cuban dissidents to national-day celebrations.