In 1988, Cuba withdrew its troops from Africa. And, since 1990, it has stopped helping the revolutionary movements. The Soviet Union collapsed in 1992, which ended the Cuban-Soviet military alliance. The US foreign policy goals were achieved, but that didn't result in any improvements in relations with Cuba, because, really, our main goal has been to topple the Castro regime....
First, Fidel Castro's personality challenged the biggest power in the world and won; he has survived nine of our presidents; and he is accepted and respected in all international forums. During the Cold War, we didn't believe it would be possible to get that stone out of our shoe. Now we do. That's why we're taking up the policies of economic pressure through the Helms-Burton Act, and of democracy and human rights....
We aren't really interested in democracy and human rights. We just use those words to hide our true reasons....
Since 1985, we have stated publicly that we will encourage and openly finance dissident and human rights groups in Cuba; this, too, is in our interests. The United States isn't financing all those groups--only the ones that are best known internationally.
Those dissidents and human rights groups in Cuba--that are nothing but a few people--are only important to the extent that they serve us in a single cause: that of destabilizing Fidel Castro's regime.
Through those two policies--economic pressure and human rights--we want to force the overthrow of Fidel Castro and then install a transitional government that we like--to reinstate the people we want and, thus control Cuba once again.
--Wayne Smith, former head of the US Interests Section in Havana 
It has nothing to do with human rights or democracy. The purpose of the US embargo on Cuba is to impose capitalism on the Cuban people by means of these cruel and inhumane trade sanctions. It won't matter what kind of elections they hold--under the terms of the embargo, socialism would never again be an option for the Cuban people. This despite the fact that Cuba's socialist system continues to this day to maintain the best health and care and education systems in the region. Control of the Cuban economy is to revert back to private hands--mostly US citizens and corporations as it turns out. This is codified in the US Helms-Burton Act.
Like any comprehensive trade embargo, the immediate objective is to destabilize the current government by creating severe hardships among the general population. It was hoped by the sponsors of this cruel and inhumane policy that the Cuban people will see these hardships as the fault not of those imposing the embargo, but as the fault of their own government! It was further hoped that the people wouldl then rise up against their own government to embrace their tormentors to the North. This hope was in vain, of course, since, even according to dissident sources, the Cuban people largely blame the embargo and those who impose it for their current hardships.
The Cuban people have on several occasions, most notably in a 1975 plebiscite (96% in favour) and in the national elections of 1993, 1998, 2003 and 2008 shown their massive support for their unique form of democratic socialism. Not wanting to take chances, perhaps, the US government would not allow the Cuban voter this choice under the terms of the US embargo. This is codified in sections 205 and 206 of the Helms-Burton Act .
Section 205 (Requirements and Factors to Determining a Transition Government) specifies, among other things, that neither Fidel nor Raul Castro may be elected to any public office.
Section 206 (Requirements for Determining a Democratically Elected Government) outlines the conditions for lifting the embargo. Among other things, it requires substantial movement to have been made toward a "market-oriented economic system based on the right to own and enjoy property." An economic system based on democratic control and collective ownership of the means of production (socialism) would simply not to be allowed.
Furthermore, section 206 requires demonstrable progress in "returning to United States citizens [or corporate entities]... property taken by the Cuban Government from such citizens and entities on or after January 1, 1959, or providing full [market value] compensation for property in accordance with international law standards and practice." Here, "United States citizen" also includes Cuban nationals in 1959 who later became U.S. citizens. This retroactive citizenship is apparently a special and unprecedented exception available only to Cuban-Americans!)
The Issue of Compensation
As a result of the Cuban Agrarian Reform Law of 1959, large-scale (largely American-owned) land holdings were nationalized. Owners of these holdings were offered compensation based on 20-year bonds at 4.5% interest for the value of these lands. This offer was rejected by the US government.
It should be noted that under international law full compensation for expropriated land is not a given as suggested by the text of Helms-Burton. According to the UN Charter of Economic Rights and Duties of States :
In any case where the question of compensation gives rise to a controversy, it shall be settled under the domestic law of the nationalizing State and by its tribunals, unless it is freely and mutually agreed by all States concerned that other peaceful means be sought on the basis of the sovereign equality of States and in accordance with the principle of free choice of means.
Thus the collective punishments meted out by Helms-Burton on the Cuban people to force a "settlement" of US claims is not only immoral, but illegal as well.
In 1996, The International Law Commission (ILC) issued their Draft Rules on State Responsibility :
[T]he ILC's 1996 Draft Rules on State Responsibility provide three conditions in which either full monetary reparations or restitution in kind might be limited: 1) where reparation would "result in depriving the population of a State of its own means of subsistence"; 2) where in-kind restitution would involve "a burden out of all proportion to the benefit which the injuring State would gain from obtaining restitution in kind instead of compensation"; and 3) where in-kind restitution would "seriously jeopardize the political independence or economic stability of the State which has committed the wrongful act, whereas the injured State would not be similarly affected if it did not obtain restitution in kind."
In Cuba's case, Luisette Gierboloni commented in the 1997 Florida State University Journal of Transnational Law & Policy :
Requiring a new, self-respecting Cuban government to commit to returning all expropriated properties to the U.S. or to provide "full compensation" for these properties in order to be recognized by the U.S. discourages the resolution of the property issue. The value of the claims against Cuba for expropriated property is estimated at over $10 billion dollars [in 1997]. Cuba's annual gross social product ("GSP") is calculated at $13.19 billion dollars. For Cuba to make a commitment to return all properties to their prior U.S. owners or to "fully compensate" them for their losses, would mean sentencing the country to financial and political devastation. For Cuba to honor such a commitment, it would have to turn over to the U.S. its entire annual GSP and levy extremely high taxes upon Cuban citizens.
Here we see that, under the terms of the Helms-Burton Act, the embargo is aimed squarely at the Cuban people. Under pain of harsh collective punishment for disobeying, socialism is be dismantled, and most, if not all, of the economic assets now owned collectively by the Cuban people is to be effectively be turned over to US citizens and corporations. Under Helms-Burton, the Revolution is to be crushed and Cuba turned into an economic colony of the US, reverting to its pre-revolutionary state. And the Cuban people are to have no choice in the matter.
Following is an excerpt from "The US attack on Cuba's health," Canadian Medical Association Journal :
In 1992 Cuba was in a severe economic depression, largely resulting from a loss of preferential trade with the Soviet bloc. Cuba turned to US foreign subsidiaries, from whom it received $500-600 million per year in imports -- 90% of which was food and medicine. The American Public Health Association warned the US government that tightening the embargo would lead to the abrupt cessation of this supply of essential goods and result in widespread famine. Indeed, 5 months after passage of the CDA [Cuba Democracy Act] , food shortages in Cuba set the scene for the worst epidemic of neurologic disease this century. More than 50 000 people suffered from optic neuropathy, deafness, loss of sensation and pain in the extremities, and a spinal cord disorder that impaired walking and bladder control.
On September 15, 1992, The Miami Herald ("Stiffer Rules on Cuba Enforced," p. 11A) reported:
The Bush administration for the first time has enforced a new regulation denying foreign ships entry to U.S. ports if they are trading with Cuba, State Department officials said Monday. A Greek-flagged freighter carrying Chinese rice to Cuba was turned away from the harbor at Long Beach, Calif. on Saturday after U.S. Customs agents alerted the Treasury Department, the officials said. The ship, which had sought servicing at the port, was ordered away under a 5-month-old U.S. policy...
The US policy of the day was clearly to starve the Cuban people into submission by blocking critical imports of food. In addition, as Gierboloni  comments on economic objectives of the embargo:
As clearly evidenced by the House Report on the Act, the purpose of Helms-Burton is to 'discourage persons and companies [outside the US] from engaging in commercial transactions in Cuba and, in doing so, to deny the Cuban regime the capital generated by such ventures.' Thus the main objective is to drive foreign investment out of Cuba.
As is well known, Cuba was dependent on imports of of much of its food and medicine for its survival. In addition to blocking imports from the US and through its ports, the Helms-Burton Act also sought to deprive the Cuban people of these critical imports from other countries by actively discouraging persons and companies outside the US from engaging in commercial transactions in Cuba. With no compensation set aside for the resulting deficits of food and medicine, we see clear evidence of the genocidal intent of the intensified US embargo in 1992. Smelling blood with the collapse of the USSR, the US government and extremists in the Cuban exile community seemed to be circling for the kill. Due to the extraordinary unity and fighting spirit of the Cuban people, however, that frenzied hope proved to be somewhat premature.
While 19% of the population in the period 1992-97 experienced some form of malnutrition (primarily vitamin and mineral deficiencies), and doubtless many in vulnerable groups died needlessly, there was no famine or mass starvation--much to the chagrin of the sponsors of this genocidal policy. Forced to make difficult choices, health care remained the top priority of the Cuban government. Prudent and effective management of very scarce resources allowed the Cuban health care system to maintain its leading position among developing nations. The Cuban infant mortality rate--the single most reliable indicator of overall public health--is the lowest in the Americas, lower that that in both Canada and the USA. 
More recently, there have been limited openings
in one one-way trade with Cuba, mostly in food and agricultural products.
Still, as even Amnesty International (May 2003) must now concede, the
embargo is still very much in force and continues to be "used to harm the most vulnerable members of society." In a
report critical of Cuba, even the UN Human Rights Commission (May 2004)
was forced to concede that, "It is also impossible to ignore the disastrous
and lasting economic and social effects of the embargo imposed on the Cuban
population over 40 years ago." Since then, new sanctions targeting
Cuban families have taken effect – family visits
been severely curtailed and remittances cut drastically. As Dennis Hays, former director of the
Cuban American National Foundation, put it so succinctly,
"What we're talking about in Cuba is enabling
the people . . . to stand up and say I can't take it any more."
(Miami Herald, June 19, 2004)
1. Hernando Calvo and Katlijn Declercq, "The Cuban Exile Movement, Dissidents or Mercenaries" p. 156, Ocean Press, 2000
Act, US Library of Congress
"UN Charter of Economic Rights and Duties of States," UN Documents, 1974
Donna E. Arzt, "The Right to
Compensation: Basic Principles Under International Law," 1999
5. Luisette Gierboloni, "Comment: The Helms-Burton Act:
Inconsistency with International Law and Irrationality at Their Maximum,"
Florida State University
Journal of Transnational Law & Policy,
6. Anthony F. Kirkpatrick, "The U.S. Attack on Cuban Health," Canadian Medical Association Journal, August 1, 1997
Mortality Rates by Country," CIA Factbook