In the last century, the United States mounted two major interventions in Haiti, both expensive failures. Before sending thousands of troops on another dubious errand, Congress and the White House would do well to ponder some lessons learned.

The first is don't do everything yourself.

In 1915, President Woodrow Wilson sent U.S. Marines to put down an uprising. They stayed for 19 years and largely ran the government. They paid off Haiti's debts, paved streets and developed Haiti's public health infrastructure. Haitian leaders largely served as figureheads. The second lesson is don't neglect cultivating a democratic political class.

In 1957, Haitians elected a country doctor - Francois "Papa Doc" Duvalier - who replaced professional troops with loyal followers. They became the dreaded Tontons Macoutes who ravaged Haiti's rural villages. When Dr. Duvalier died in 1971, his son, Jean-Claude, became president for life - until the army toppled him.

After the ouster of "Baby Doc," the Reagan administration encouraged Haitians to adopt a democratic constitution but neglected to put much effort into cultivating an educated political class. In 1990, they elected a former parish priest, Jean-Bertrand Aristide, as president. Having participated in Dr. Duvalier's ouster, Mr. Aristide was wildly popular.

Like the Duvaliers, Mr. Aristide had little political or administrative experience. Instead of building institutions to support a newly adopted democratic constitution, he encouraged street gangs to silence critics. His presidency lapsed into chaos. Within months, his security chief, Gen. Raoul Cedras, deposed him and named a governing junta.

Mr. Aristide fled to the United States and drew on frozen Haitian bank accounts. Prodded by Congress and Mr. Aristide's lobbying, the Clinton administration abandoned negotiations and restored him by invading Haiti - committing about $3 billion and 20,000 U.S. troops in the process. In doing so, U.S. officials made another mistake - they promoted a demagogue over rebuilding political institutions.

Freshly reinstalled, Mr. Aristide made himself the center of attention. While foreign advisers and aid workers worried about rebuilding the police and judiciary, he renewed ties to partisan gangs. He even had to be talked out of staying beyond his constitutional term to allow his elected successor and protégé, Rene Preval, to take office in December 1995.

Out of office, Mr. Aristide ruled through the pliant Mr. Preval. Haiti was without an elected parliament for two years, succeeding elections were marred by fraud and progress on the police and judiciary was undone by Mr. Aristide's political appointments to those institutions. The United States and multilateral donors curtailed direct assistance to the government.

Returning to office through controversial elections in 2000, Mr. Aristide continued to disappoint. To restore aid, he promised President Bill Clinton to correct flawed elections, improve respect for human rights and include members of the growing political opposition in his administration. He gave similar assurances to the Organization of American States but never followed through. Suspicious of his record, the growing democratic opposition was reluctant to cooperate with him.

With Mr. Aristide's departure, another intervention is under way. This time, the United States and its allies have shown remarkable restraint - refusing to take sides until it was necessary to avoid violence against the president and his family. Moreover, they have refused to take over. They seem to have learned the first lesson.

Haiti's interim leaders need to forge a new peace on their own, without excessive advice and conflicting signals from interested foreign powers. This is Haiti's fight. For now, help should come in the form of peacekeepers and good offices.

Further, Haiti needs an educated political class. But that doesn't mean polishing existing elites. Haiti should have a broad base of educated citizens who can practice democratic government from their neighborhoods to the national level. Citizens should know their rights as well as responsibilities and be able to measure the performance of those who serve them in office. After public order is established, promoting education and the development of civil society must become support priorities.

Moreover, the United States and the international community should avoid placing faith in demagogues. Mr. Aristide used the Haitian and U.S. governments to get rich while polarizing and destabilizing his nation. This sad experience should teach us not to back a figure so personally ever again.