Originally a Spanish colony, Cuba was "liberated" by the United States in 1898 at the conclusion of the Spanish-American War. It was then controlled for a good many years by US-backed dictator Fulgencio Batista. Since 1959 it has been run for almost fifty years by Fidel Castro, despite assassination attempts by the CIA too numerous to count. Until the fall of the Soviet Union, Cuba was the USSR's major Western Hemisphere ally.
Located ninety miles off the coast of Florida, Cuba poses a grave threat to U.S. sovereignty... or tourist dollars, anyway — though the US has maintained a trade blockade against Cuba since 1962, it is honored by almost no one else in the world, making Cuba a popular destination for European tourists who want to go somewhere that isn't overrun by Americans.
Cuba was America's playground in the Caribbean, a holiday destination with casinos (before Las Vegas became a thing) where US corporations were able to do as they pleased with a compliant banana republic government doing their bidding. Once the revolution turned Communist and you had the combination of the wealthy exiles and nationalization of American assets, it was a perfect storm for the embargo to be put in place. It's arguable Castro wouldn't have embraced Communism had the US reacted more cooperatively with the new reality in post-revolution Cuba. Instead, Cuba's isolation pushed them into the Soviet sphere of influence, leading Castro to fully embrace Communism as the only means of ensuring the long-term success of his revolution.
The scale and scope of the crimes committed by the Castro regime aren't necessarily unprecedented in history, but a key difference is that a massive number of their victims fled to become full-fledged US citizens in one of the few true swing states in the country. Suddenly you had two special interest groups in the US who are vehemently against normalization of relations: the corporations that lost their assets and the Cuban exiles. The former doesn't make much noise anymore, but the latter is still influential—many still refuse to vote Democrat because Kennedy didn't lend aid to the counter-revolutionaries. (Let's be real though; if Cuban refugees all settled in Vermont then they would have a lot less say in national politics. Florida is essential to the electoral math.)
Multiple diplomats, US military officials and businessmen are now calling for easing (or even lifting) the embargo, which has been condemned by the United Nations every year since 1992. On August 14, 2015, the United States reopened its embassy in Havana, officially reinstating diplomatic ties with Cuba.
Cuba And Terrorism
From 1982 to 2015, Cuba had been on the United States Department Of Defense "State Sponsors Of Terrorism" list, which claims that these countries have "repeatedly provided support for acts of international terrorism" . along with (at the time) four other countries, due to their quite open support and armament of revolutionary movements in several different Third World nations. The U.S Department itself claims that
"Havana openly advocates armed revolution as the only means for leftist forces to gain power in Latin America, and the Cubans have played an important role in facilitating the movement of men and weapons into the region. Havana provides direct support in the form of training, arms, safe havens, and advice to a wide variety of guerrilla groups. Many of these groups engage in terrorist operations" 
Cuba was removed from this list on May 29, 2015. On the other side, Cuba has been subject to many terrorist attacks, some from the rogue Nationalist faction within Cuba, such as the 1997 hotel bombings or come indirectly from America, such as infamous "Bay of Pigs" invasion, which was fought by U.S-trained Cuban insurgents, and was organized by the top United States military brass, personally signed and commenced by JFK himself. The CIA also organized "The Cuban Project" which was a large scale project involving attacks on markets, shopping malls, and other densely populated areas of Cuba in order to, as the protocol states, "to lure or provoke Castro, or an uncontrollable subordinate, into an overt hostile reaction against the United States; a reaction which would in turn create the justification for the US to not only retaliate but destroy Castro with speed, force and determination."
Cuba and democracy
The United States and opponents of the Cuban communist government accuse the Caribbean country of being a dictatorship and violating human rights. Supporters of Cuba disagree and argue that there is no United Nations determination for what is the right model of democracy and no requirement for a multi-party system and say the nation is a grassroots popular democracy, where political processes are taken to the lowest level of social organization. The idea of a single-party system was not conceived by the communists, but in 1892 by José Martí, liberal independence leader, to unite Cubans against foreign domination and was approved by the Cuban people in 1976, when more than 97% voted for in favor of the new constitution, after exhausting grassroots discussions that involved millions of citizens and changed several articles. Since 1992, opposition parties are also permitted and legally, the Communist Party and any of its possible opposition does not control the electoral process and is not allowed to campaign or endorse anyone. Any Cuban over 16 is allowed to run for elections and vote in a secret ballot. Candidates are nominated by local assemblies and any person has the right to suggest a nomination. Cubans are politically active and elections usually have over 90% turnout, although voting is not mandatory. However, the US State Department and Human Rights Watch state that Cuban elections are neither free nor fair. Although voting is not legally required, citizens are pressured to vote by the Committees for Defense of the Revolution (CDRs), state organizations closely aligned with the police and security services, which along with them monitor electoral meetings. Additionally, the media is state controlled and uniformly supports the government-approved candidates. All opposition political activities are effectively outlawed, with numerous dissidents imprisoned, making attempting political change peacefully a dangerous prospect. The legislature, even if it was freely elected, is also virtually powerless. It meets only a few days each year, with most business conducted by a government-controlled standing committee. In practice, higher offices require Communist Party membership.
Health in Cuba
Cuba's national health program provides universal healthcare to all of its citizens; however, the program (as well as the economy overall) was vastly weakened by the United States embargo, the fall of the Soviet Union, and the fact that collective planning is terrible for providing services that private capital would usually cover (e.g. not health care).
Moreover, the United States imposed a tight prohibition on subsidiary trade in food and medicine to Cuba in 1992 with the passage of the Cuban Democracy Act (which obviously failed to live up to its name). The Act forbade ships that dock in Cuban ports from docking in U.S. ports for six months. This drastically inhibited shipping, and increased shipping costs about 30%. Because of the nature of the trade prohibited, this embargo has been accused of violating international law. Restrictions on medicinal imports are so extensive that it is nearly impossible for Cuba to import medicines from the US. Some of these restrictions include provisions that Cuba must make all payments in cash and in advance, cannot obtain credit, either public or private, and that Cuba cannot use its own merchant vessels to transport the goods.
After the end of USSR subsidies to Cuba, there was a period of economic shock and turmoil; this greatly affected the quality the national health care service. However, in recent years, it has seen surprisingly substantial recovery and ample improvement. For example, Cuba became the first country to develop and market a vaccine for meningitis B, and its hepatitis B vaccine is being exported to thirty nations worldwide. In addition, according to the World Health Organization, Cuba provides a doctor for every 170 residents (ahead of the US where the ratio is 1 to 188) and does fine on infant mortality and life expectancy rates.
- On February 24, 2008 his brother Raúl Castro was elected as the new President.
- Negroponte Leads Group Urging Obama to Ease Cuba Embargo, Bloomberg
- Guillermo Farinas was released from prison to be hospitalised, despite the fact that he was using civil disobedience in an attempt to provoke reform. 
- Raúl Castro to allow Cubans more private sector jobs, The Guardian
- Health Situation Analysis and Trends Summary: Cuba, Pan American Health Organization
- An Evaluation of Four Decades of Cuban Healthcare, SUNY Buffalo
- BMA must voice its opposition to Cuban embargo, British Medical Journal
- Assembly Again Seeks Repeal of Extraterritorial Measures Like United States Helms-Burton Act Against Cuba, UN
- Medical know-how boosts Cuba's wealth, BBC News
- Country Comparison: Infant Mortality and Life Expectancy at Birth, CIA