Mark Weisbrot is co-director of the Center for Economic and Policy Research, in Washington, D.C.

In 1915 the U.S. Marines invaded Haiti, occupying the country until 1934. U.S. officials rewrote the Haitian constitution, and when the Haitian national assembly refused to ratify it, they dissolved the assembly. They then held a "referendum" in which about five percent of the electorate voted and approved the new constitution – which conveniently changed Haitian law to allow foreigners to own land – with 99.9 percent voting for approval.

The situation today is remarkably similar. The country is occupied, and although the occupying troops wear blue helmets, everyone knows that Washington calls the shots. On November 28 an election was held in which the country's most popular political party was excluded; but still the results of the first round of the election were not quite right. The OAS – under direction from Washington – then changed the results to eliminate the government's candidate from the second round. To force the government to accept the OAS rewrite of the results, Haiti was threatened with a cut-off of aid flows – and, according to multiple sources, President Preval was threatened with being forcibly flown out of the country, as happened to President Jean-Bertrand Aristide in 2004.

Now Aristide has been issued a diplomatic passport by the government, and is preparing to return. But Washington does not agree , as U.S. State Department spokesman P.J. Crowley made clear yesterday. He was also asked if the U.S. government had pressured either the Haitian or South African governments to prevent Aristide's return. He refused to answer; I take that as a "yes."

The United States has been the prime cause of instability in Haiti, not only over the last two centuries, but the last two decades. Although Haiti is a small and poor country, Washington still cares very much about who is running it -- and as leaked Wikileaks cables recently demonstrated, they want a government that is in line with their overall foreign policy for the region. In 1991, Aristide Haiti's first democratically elected president was overthrown after just seven months in office. The officers who carried out the coup and established the military government, killing thousands of innocent Haitians, were subsequently found by the New York Times to be in the pay of the U.S. Central Intelligence Agency.

When Aristide was elected to a second term, in 2000, the United States and its allies destroyed the economy through an economic aid cutoff. Together with aid to the Haitian opposition and an armed insurrection, Washington's effort succeeded in overthrowing the government four years later.