If any proof were needed that terrorists tied to President Aristide, the ousted leader, are determined to wreck the peace in Haiti, we got it on Wednesday. And if no coordinated effort is undertaken immediately to deal with them, they will have won just by maintaining a climate of fear in the country.

While Secretary of State Powell was at the palace in Port-au-Prince meeting with President Boniface and Prime Minister Latortue, thugs in a speeding vehicle exchanged fire with defenders crouched in battle position behind their vehicles inside the fenced perimeter of the palace, the ultimate symbol of power.

Meanwhile, press reports say that some three blocks away, in the trouble zone of BelAir, heavy gunfire was heard for nearly one hour, giving the impression that war had erupted in Port-au-Prince. The streets around the palace were quickly deserted. Specialized assault units of the national police and soldiers of the Minustah, as the U.N. mission to stabilize Haiti is called, sealed the zone surrounding the palace. The attackers disappeared in a flash. Three people were reportedly killed and nine were wounded, including two high school students and a medical doctor.

The life of Mr. Powell and those of the Haitian officials were never in danger, the reports say. But that probably was not the intention of the terrorists, who aimed to scare and disrupt normal activities. In that sense, they’re playing the game of “qui perd gagne,” or “loser wins,” meaning they gain just by playing spoiler.

Indeed, the Aristide supporters, a dwindling band of thugs, have created a climate of fear mainly in Port-au-Prince, since they unleashed their “Operation Baghdad” September 30.

The latest spectacular attack in Port-au-Prince failed to rise to the level of that against the French secretary of state for foreign affairs, Renaud Muselier, who was trapped last August inside Cite Soleil, the vast shantytown north of the capital reputed as a bastion of Mr. Aristide. Armored cars of the Minustah had to extirpate Mr. Muselier from a precarious situation. The French official had pointedly denounced the supporters of Mr. Aristide for their attack on him.

Undoubtedly, the two attacks are also meant as retribution against France and America, whom Mr. Aristide had blamed for his ouster. Actually, those two uncomfortable allies since the Iraq war teamed up last February to save Mr. Aristide’s life. Faced with a widening internal revolt and pressured by the international community, Mr. Aristide finally chose to resign and sought American protection to leave Haiti. Initially, France convinced one of its allies – the Central African Republic – to accommodate the fallen president, who didn’t have a place to go. Once safely out of Haiti, Mr. Aristide asserted that he was “kidnapped” by American agents in collusion with France. After two weeks in Central Africa, he was flown back to Jamaica, to the displeasure of Mr. Powell and President Bush’s national security adviser Condoleezza Rice, who publicly voiced their opinion. Eventually Mr. Aristide found refuge in South Africa, where President Mbeki remains an ally of his.

It is fitting that Mr. Powell revisited Haiti to see firsthand the unfinished task that Ms. Rice will no doubt inherit with her confirmation as secretary of state. Perhaps she will have to resort to the Powell Doctrine of overwhelming force eschewed last February in dealing with the heavily armed thugs left behind by Mr. Aristide.

A reassessment of the situation is definitely in order in the wake of Wednesday’s attack. Perhaps the American authorities should act on the demand of the French ambassador to Port-au-Prince, Thierry Burkard. In an interview November 23 to Vision 2000, a Port-au-Prince radio station, Mr. Burkard said from his exile in South Africa, Mr. Aristide “has a nuisance capability” that shouldn’t be allowed to turn into “a political capability.” To that end, he begged America “to deal rapidly, concretely, and efficiently with the dossier of drugs in Haiti as well as with other dossiers of financial embezzlement that are privy to the American authorities.”

In other words, if Mr. Aristide were to be indicted for his alleged involvement in drug trafficking, as several of his lieutenants have already been, he couldn’t continue to cause problem by proxy all the way from South Africa. He might even join seven of his closest associates in federal jail in Florida.

Thus, without dispatching thousands of troops to the Caribbean island nation, America disposes of leverage to bring a halt to a brazen destabilization process now going on at its doorstep.

Mr.Joseph is Haiti’s envoy to Washington.