HAITI STOOD on the verge of revolution or anarchy last night. Armed gangs opposed to President Jean-Bertrand Aristide controlled a number of towns, and fighting was reported in the second-largest city, Cap Haitien. Scores have been killed since rebellion began last week, and the United Nations is warning of an imminent food crisis. Yet neither the United States nor Haiti’s other neighbors appear prepared to come to its rescue. They are standing by as a violent movement, made up at least in part of criminals and thugs with connections to Haiti’s last dictatorship, overthrows a democratically elected president — or is itself brutally put down.

The lack of American activity is a strange sequel to the 1994 U.S. invasion that restored Mr. Aristide to power, and irresponsible considering the potential for another mass movement of Haitian refugees to the United States. But senior Republican and Bush administration officials are loath to help Mr. Aristide, whose restoration they opposed. Though the State Department has issued calls for an end to the violence, little has been done to discourage Mr. Aristide’s opposition from thinking it can and should oust the president by force — an act that ought not to be condoned against an elected leader. Some officials may believe that such an outcome might make possible an end to years of political crisis and conflict in Haiti, much of it caused by Mr. Aristide. If so, they are probably wrong.

Mr. Aristide, once a populist priest, has cruelly disappointed Haitians who believed he would consolidate democracy and begin to develop the Western Hemisphere’s poorest country. Though his own election was fair, he has tolerated fraudulent manipulation of parliamentary elections and violence by his supporters against journalists, human rights activists and others who oppose him. He has repeatedly promised compromise and reform, and failed to deliver. This month, however, Mr. Aristide agreed to a list of demands from a group of Caribbean countries known as Caricom, including the establishment of a joint advisory council with opposition groups.

The leading opposition political organizations call themselves democratic, but they have refused any solution short of Mr. Aristide’s removal from office. For weeks they have been conducting demonstrations and strikes, sometimes with violent results. Now they seem to hope they can capitalize on the armed rebellion, which was initiated in the city of Gonaives by a gang of toughs that once was allied with Mr. Aristide but broke with him last year. It’s foolish to expect that a victory of the street fighters over the president’s police force will open the way to more liberal government or an end to violence. Haiti’s only hope is a forceful diplomatic intervention and a brokered political solution. That will require the United States to play a leading role, not hand off responsibility to Caribbean diplomats. If the Bush administration gives in to the temptation to sit on its hands in the hope of seeing Mr. Aristide’s downfall, it will only invite more misery — in Haiti, and very likely, in the seas between the island and Florida.