– Bernd Debusmann is a Reuters columnist. The opinions expressed are his own –

The U.S. case for isolating Cuba and keeping it out of international meetings such as this week’s Summit of the Americas sounds simple: the country doesn’t have democratically elected leaders, it holds political prisoners, it violates human rights and its citizens can’t travel freely. All perfectly true.

But if the logic used for isolating Cuba were applied consistently, neither China nor Saudi Arabia, for example, should have taken part in the London G20 summit. The U.S. State Department estimates China has “tens of thousands” of political prisoners and describes it as “an authoritarian state in which the Chinese Communist Party … is the paramount source of power.”

That has made little difference to the close relationship of mutual dependence between the U.S. and China, the largest creditor of the United States. During U.S. Secretary of State Hillary Clinton’s February visit to China, pragmatism triumphed over human rights concerns as she urged the Chinese to keep buying U.S. treasury bonds.

In comparison to China’s “tens of thousands,” the State Department’s latest human rights report quotes a Cuban human rights group as saying the government there held at least 205 political prisoners at the end of 2008, down from 240 at the end of 2007.

The Saudi monarchy, according to the State Department report, denies its citizens the right to change the government peacefully, holds political prisoners, curbs free speech, restricts religious freedom, tolerates violence against women, and sanctions corporal punishment. The list goes on and includes lack of due process in the judicial system.

If the logic applied to Cuba were consistent, U.S. citizens should be banned from traveling to North Korea, an “absolute dictatorship” where the State Department noted extrajudicial killings, disappearances, arbitrary detentions, and political prisoners. Instead, the only country to which the U.S. government restricts travel by its citizens is Cuba.

In advance of making his first appearance at a Hemispheric summit this week, U.S. President Barack Obama eased restrictions his predecessor, George W. Bush, had imposed to make it more difficult for Cuban-Americans with relatives on the island to travel and send money there. Obama also allowed U.S. telecommunications companies to bid for Cuban licenses.

These are small steps that fall far short of lifting the 47-year-old U.S. trade embargo on Cuba, a Cold War measure that demonstrably failed in its aim to bring down the communist government of Fidel Castro, who defied 10 successive U.S. presidents, both Democrats and Republicans, before he formally handed power to his brother Raul last February due to a long illness.

HAVANA-WASHINGTON THAW?

Raul Castro, who is 77 and was Cuba’s defense minister for almost five decades, has since made several key changes in the leadership. They included firing foreign minister Felipe Perez Roque, one of a group of young officials whose dedication to Fidel Castro was so fierce they earned the nickname “tropical Taliban.” He was replaced by Bruno Rodriguez, a less doctrinaire foreign service veteran.

Some Cuba watchers saw this change as a move to facilitate efforts to thaw relations between Havana and Washington. How far and how fast Obama will go is certain to be a topic at the summit in Trinidad and Tobago where Cuba is the only country in all the Americas not invited.

Advocates of lifting the embargo, a policy change that would finally bring the United States in line with the rest of the world, see light at the end of the long tunnel. “This is the beginning of the end of the worst, least successful foreign policy experiment in the history of the United States,” in the words of David Rothkopf, head of a consultancy who blogs at Foreign Policy magazine.

Wishful thinking? Lifting the embargo would require repealing legislation — including the controversial 1996 Helms-Burton law - that penalizes companies doing business with Cuba. In one of its more bizarre interpretations, U.S. pressure resulted in Mexico City’s Sheraton hotel expelling a 16-strong Cuban delegation attending an energy conference there a few years ago.

The beginning-of-the-end school of thought points to legislation now pending - The Freedom to Travel to Cuba Act - which would allow all Americans, not only Cuban-Americans with family on the island, to visit. If that act were passed, a study for the International Monetary Fund estimates that up to 3.5 million Americans could visit annually.

Cuba is not on the official agenda of the Trinidad summit (the fifth in a series that began in Miami in 1994) but Venezuela’s left-wing, anti-American president, Hugo Chavez, is certain to bring it up, along with a demand that the 34-member Organization of American States readmit Cuba. Its membership was suspended in 1962.

The guideline that only democratically-elected leaders can take part in summit meetings dates from the 1994 gathering - and even then, the logic was flawed. The Miami meeting’s participants included then Peruvian President Alberto Fujimori, a leader of dubious democratic credentials whose acts in office included dissolving Congress and closing the country’s courts.

He then won elections boycotted by the opposition. This month, a Peruvian court sentenced Fujimori to 25 years in jail for human rights abuses and involvement in two military massacres during a campaign against left-wing guerrillas.

Obama campaigned for president on a platform of “change we can believe in.” His moves on Cuba will provide a good indicator of how much of a change agent he really is.