U.N. diplomats did their best to put a smiley face on the grim picture in Haiti during a weekend visit, but no amount of diplomatic artistry can conceal the ugly truth: Haiti is back to one-man rule, and no one can say how long it will last.

The high-profile visit by representatives of the U.N. Security Council, including U.S. Ambassador Samantha Power, was meant to show the international community’s concern over Haiti. Such gestures are helpful, given that the poorest nation in the Western Hemisphere desperately needs the world community’s support to make any progress whatsoever.

But even though it’s customary for visiting dignitaries to say nice things about the host government, the delegation nearly went overboard in praising President Michel Martelly for consulting with the opposition and civil-society groups now that constitutional government has broken down. They were “encouraged,” Ms. Power said, about his promise to keep working at it.

Many discouraged Haitians would beg to differ. Mr. Martelly has been at the center of Haiti’s political turmoil ever since he took office in May 2011. Today, the country is embroiled in a political crisis that has left it with no elected mayors, no head of the Supreme Court and no Chamber of Deputies or working Senate.

A failure to hold elections overdue by more than three years caused the terms of most lawmakers to expire this month. Now Mr. Martelly governs by decree.

The president is not the problem per se. Certainly the electoral impasse cannot be laid solely at his feet. But just as certainly, he’s a big part of it. Throughout his tenure, he has failed to work with adversaries to reach political compromises. His opposition has been just as stubborn, but it’s Mr. Martelly who bears the burden of leadership and during whose watch the country has suddenly regressed to one-man rule.

In an address to the nation days before the U.N. delegation arrived, the president accepted the responsibility for the crisis and promised to reach out to his political opponents to hold credible elections later this year.

That’s a refreshing change, but he’s not off to a good start. He handed all the critical ministries in the interim government to his own followers, including some who would probably be unable to get a clean financial bill of health under provisions of Haiti’s Constitution. Mr. Martelly says he wants to turn the page, yet was about to name a discredited cop to a high government post until the international community warned against it.

All of this suggests Mr. Martelly does not respect the processes of democratic government, which brought him to office, ironically, and often require sharing power with adversaries. Those adversaries, for their part, need to realize that Mr. Martelly is the only president Haiti has. They have to be ready to meet him halfway if he is sincere about reaching out.

The role of the international community in breaking the political stalemate will be crucial, but it doesn’t help when the community’s representatives offer blind support for the president. Diplomats face a credibility problem because they’re seen as enablers instead of impartial mediators.

As he enters the last year of his tenure, Mr. Martelly’s main task is to restore political trust in Haiti. He has a chance to be one of the best presidents Haiti has had by staging free, fair and transparent elections — not for himself or a protégé, but for all candidates. If he fails, he will end up as ill-regarded as some of his terrible predecessors. Or worse.