In his first six weeks on the job, Ambassador Richard C. Holbrooke, the permanent U.S. representative to the United Nations, has negotiated an intervention force for East Timor, surveyed mass graves in Kosovo and enlisted the Security Council's support in the pursuit of Saudi militant Osama Bin Laden. But what really stirs him up is what he calls "the big small thing": a high-level campaign, involving President Clinton, to regain an American seat on an obscure U.N. budget committee.

The recent success of the campaign, Holbrooke said, may help convince moderate Republicans in Congress that the United States should pay its debts to the world body, which total about $1 billion by the U.S. count and $1.7 billion by the United Nations' tally.

Whether Holbrooke can parlay such hard-won American victories at the United Nations into congressional support for the cash-strapped organization will affect the United Nations' ability to afford a series of new peacekeeping missions.

"I would hope that Washington, which has been so concerned about Kosovo and East Timor and Sierra Leone and the Democratic Republic of Congo, will find the resources to make [these operations] viable," Secretary General Kofi Annan said in an interview. "It's not enough to vote a mandate and not offer the resources."

Whether the United States remains the biggest deadbeat at the United Nations also has a bearing on the future of Holbrooke, who may be a candidate for secretary of state if a Democrat wins the 2000 presidential election.

"He's got a big job and [Al] Gore and [Bill] Bradley will be looking to see how effective he is at resolving this issue," said William Leurs, president of the nonprofit United Nations Association.

Two years ago, the Senate passed a bipartisan bill, co-sponsored by Sens. Jesse Helms (R-N.C.) and Joseph R. Biden Jr. (D-Del.), to pay $926 million in arrears to the United Nations on the condition that the world body cut its budget, undertake administrative reforms and sharply reduce the U.S. share of its operating costs. But Rep. Christopher H. Smith (R-N.J.) repeatedly has attached antiabortion language to the legislation, prompting Clinton to veto it two years in a row. It is unclear whether Smith will attach the abortion rider, which restricts U.S. funding for family planning organizations overseas, to the bill again this year.

Holbrooke has been assiduously courting moderate Republicans and antiabortion Democrats, including Rep. Tony P. Hall (D-Ohio), in an attempt to disentangle the payment of arrears from the abortion issue. He hosted a bipartisan delegation on a visit to the United Nations last month. He also invited diplomatic luminaries, including Annan and Henry Kissinger, to a dinner honoring Sen. Rod Grams (R-Minn.), chairman of the subcommittee on international operations.

"We presented him with a gift," said Holbrooke, referring to the restored U.S. seat on the budget committee, one of several preconditions laid down in the Helms-Biden bill. "Our presence means we're back in the debate on the budget. Now we have to go to Washington to show we are fulfilling the Helms-Biden legislation even before it has reached the president."

Holbrooke said his next priorities are blocking a request by the U.N. secretary general for a slight increase in the organization's 2000-2001 budget and building foreign support for a reduction of the U.S. share of the United Nations' administrative budget from 25 to 22 percent.

The campaign to reclaim a seat on the Advisory Committee on Administrative and Budgetary Questions--which the United States lost in 1996 for the first time since the United Nations' birth--provides a glimpse of Holbrooke's strategy.

Because the United States was rebuffed in an attempt to regain the seat in November 1998--in large part because of anger by other countries at the U.S. failure to pay its debt--Holbrooke asked Clinton to intervene personally this year. At a meeting of Asian leaders in Auckland, New Zealand, last month, Clinton asked New Zealand Prime Minister Jenny Shipley to give up her country's seat to make way for an American.

Holbrooke and Secretary of State Madeleine K. Albright followed up with a doubled-barreled assault on foreign dignitaries at the U.N. General Assembly, warning virtually everyone they met that the United States had better get its way.

"A vote against the U.S., no matter how good it feels, is a vote against the United Nations," Albright warned one group of European diplomats, according to a senior U.S. diplomat. She was even blunter with the New Zealanders, the official said. "If you win, you lose," Albright said, according to the official, "because the United Nations is going to go down with you."

"I really learned a lesson," said Holbrooke. "We won this by taking it out of the U.N. village."

Supporters of the United Nations have voiced concern that the payment of arrears still could be foiled by spending caps, partisan politics or the abortion issue.

"It's going to take a lot of work for Dick, the secretary of state, and above all President Clinton to begin changing some votes," said Leslie Gelb, president of the Council on Foreign Relations. "For all Dick's skills, this is a job that still requires the man in the White House."

Even British officials, who were key allies in the battle over the budget committee, show exasperation over Washington's continued refusal to pay its bills.

"The United States has muffled its voice and stained its reputation by . . . being the largest debtor, persistently and perennially," said Sir Jeremy Greenstock, Britain's ambassador to the United Nations. "I welcome Ambassador Holbrooke's commitment to change all that. He has not got much time."