Diplomacy has never been the strong suit of President Bush's administration. No wonder the Senate balked last year at confirming cantankerous John Bolton as United Nations ambassador, leading to his recess appointment by Bush.

Bolton turned in his resignation yesterday after it became clear that the Senate Foreign Relations Committee would not approve returning him to his post. His 16-month term, shortened because the Senate had not confirmed him, expires at the end of December.

Not surprisingly, the president praised his man at the U.N. Monday. It was a maddening assessment based on the world according to Bush — an interpretation that voters rejected last month.

The president said he had been confident when he appointed Bolton that his envoy would "represent America's values and effectively confront difficult problems at the United Nations."

Bolton didn't represent America's values as much as he represented the Bush administration's devaluing of multilateralism and the United Nations. His was a bullying style that was better at discouraging than persuading other nations to sign on to U.S. proposals and priorities.

Bolton said he wanted to help the United Nations improve its operations. But it was never clear whether he really wanted to do so, or was more interested in finding enough faults to justify the United States' retreating still more from international organizations and agreements.

One example: Bolton had a chance soon after he became ambassador to help pass a U.N. reform plan that had been long in the making, and that included operational changes the United States sought. Instead, he upended the plan by insisting that the General Assembly agree to 400 last-minute revisions he presented.

"He is very good on preaching on reform but not good at doing it," Edward Luck, a U.N. scholar at Columbia University, told Reuters.

Bolton can claim some achievements, most notably Security Council actions against North Korea and in response to the genocide in Darfur. But the United States rarely has been able to utilize the United Nations to advance its goals, even as the war in Iraq has shown the difficulty of a go-it-alone approach.

With two years remaining for the Bush administration, it would be heartening if the president named a successor who aggressively sought smart U.N. reforms and had the diplomatic skills to bring other nations along. Some who are rumored to be possible Bolton successors, including U.S. Ambassador to Iraq Zalmay Khalilzad, hold the promise of that.

But whoever is the American ambassador to the United Nations can do only as much as his bosses in the State Department and the White House allow him to do.

It would be good for the nation if the administration used Bolton's departure as an opportunity to strengthen the United Nations in a time when global cooperation is essential. Bush's record, and his praise of Bolton, do not bode well for that happening.