When the deal to end the war in Kosovo struck like lightning last week, it caught exhausted negotiators at their darkest moment.

At 4 a.m. on Wednesday, after 13 hours of talks in a German government guest house, Deputy Secretary of State Strobe Talbott, Russia's Balkans envoy Viktor Chernomyrdin and Finnish President Martti Ahtisaari had failed to find agreement on a peace plan they could present to Belgrade. Distraught and dispirited, they realized they were facing disaster as they broke up for a few hours of sleep.

But as the envoys regrouped for a climactic breakfast session at the Petersberg castle overlooking the Rhine, the American delegation was stunned to learn that Moscow had approved a simple but critical concession. The Russians accepted NATO's key demand that all Yugoslav armed forces and paramilitary police -- not just some -- should quit Kosovo so that nearly 1 million ethnic Albanian refugees could return to their homes.

Agreement on the word "all" would, in a single day, free negotiators from of a diplomatic maze in which the talks had been trapped for weeks. By two o'clock Wednesday afternoon, Chernomyrdin and Ahtisaari, the European Union's representative, were speeding toward Cologne's military airport to deliver a two-page document to Belgrade. Within 24 hours, the Yugoslav authorities would embrace the entire document -- in Talbott's words, "down to the last punctuation point" -- that established their terms of surrender to NATO's 11-week bombing campaign.

The deal seemed to catch all parties by surprise except, oddly, the Yugoslav government. For the United States and its allies, the breakthrough was a spectacular reversal of fortune at a time when the Clinton administration and European leaders were coming to terms with the possibility that an invasion of Serbia -- despite incalculable costs -- might be necessary to achieve NATO's war aims. For Russia, it represented a turnaround from strident criticism of NATO's positions, which Chernomyrdin said had set back U.S.-Russian relations by decades.

At its core, according to accounts by participants on all sides, the story of the Kosovo deal is as much about how NATO obtained the agreement of the Russians as it is about forcing consent from Yugoslav President Slobodan Milosevic. During a month of high-stakes and high-wire diplomacy -- with Milosevic's presence represented, at one point, by an empty chair at the table -- American and European officials sought to persuade Russia to use its influence with its Yugoslav ally to secure the concessions that would bring peace.

To do that, negotiators believed, they first had to convince Russia that its long-term security interests lay with the West and not with its Slavic brothers in Belgrade.

The Chernomyrdin Connection

To make the Moscow-Belgrade contacts work for them, Europe and U.S. officials needed their own mediator. This was the message Chernomyrdin brought to Washington during a visit on May 3, proposing in a meeting with President Clinton that the Western powers should name their own representative in the talks.

"I can't take Yugoslavia's surrender, that's not my job," he was quoted by a senior administration official as telling Clinton. "It would be useful if I had someone in whom you had confidence, to whom such an acceptance of NATO's conditions could be given."

A month earlier, Chernomyrdin's appointment by President Boris Yeltsin as Russia's Balkans envoy had inspired confidence in the Americans. The former prime minister had cultivated close ties with Vice President Gore as joint custodians of the Russian-American dialogue.

But Chernomyrdin adopted a hard line against NATO and the West at the start of his mission. Despite a rivalry with Foreign Minister Igor Ivanov -- and a reportedly cool relationship with Milosevic -- Chernomyrdin was a strong advocate of the government's demand that NATO stop the bombing as a sign of good faith in his mediation effort. The United States and its allies refused to suspend airstrikes unless Milosevic started pulling troops out of Kosovo.

Russia supported Yugoslavia's insistence that no foreign troops, especially those from NATO countries, should be allowed on Yugoslav territory.

"When you say Serbia and Kosovo, Chernomyrdin thinks of Russia and Chechnya," said NATO Secretary General Javier Solana, referring to the breakaway province that tried to secede from Moscow's rule. "The Russians are always worried that NATO wants to exploit their insecurities."

As a wounded former superpower, Russia was seething with resentment over NATO's decision to launch its first attack on a sovereign state, despite its claim to be a purely defensive alliance. In the wake of NATO's recent expansion toward Russia's doorstep, the bombing of Yugoslavia was seen as a hostile expression of NATO ambition at a time of Russian weakness.

Political disarray in Russia compounded the difficulty of nurturing a partnership in the search for a solution to the Kosovo crisis. With Yeltsin seen as an ailing and erratic leader, Russian politicians -- including Chernomyrdin -- are jockeying for power as they maneuver ahead of presidential elections. In the current political climate, rhetorical broadsides against the West are more fashionable than at any time since the collapse of the Soviet empire.

Through April and into May, while the Serbs pressed ahead with the deportation of nearly a million ethnic Albanians, Chernomyrdin's mission appeared to be going nowhere.

During an hour-long breakfast at Gore's house during Chernomyrdin's May 3 visit, the envoy and the vice president discussed possible candidates for a European representative who might speed development of a peace plan. Secretary of State Madeleine K. Albright suggested Ahtisaari, a former diplomat and U.N. envoy who had experience with peacemaking missions in Africa and the Balkans. As president of a neutral country that is also a member of the European Union, Ahtisaari was also highly respected by the Russians.

"Chernomyrdin is very pragmatic, a problem solver, and he's very astute about how you make things happen," Albright said. "What he wanted was a partner who would be able to help him in delivering the message."

Three days later, Russia and the United States, joined by six other leading industrial democracies, achieved an important understanding. The Group of Eight foreign ministers approved a document spelling out the "general principles" for a Kosovo settlement.

While Russia still objected to NATO playing a central role in a peacekeeping force, Moscow for the first time endorsed the need for "an effective international security presence" in Kosovo once Yugoslav forces withdrew.

The Trilateral Waltz

The job of nailing down the details of the G-8 principles and bridging the remaining gaps between Russia and the West became a full-time obsession for Chernomyrdin, Talbott and the newly appointed Ahtisaari. Over the next weeks, they would meet four times -- in Bonn, Helsinki and twice in Moscow -- for more than 50 hours of intense discussion.

None of the men realized how difficult their encounters would turn out to be. "They were emotionally and physically tense," said Valentin Sergeyev, a close Chernomyrdin aide who traveled with him throughout the mission. He said their task was complicated by mounting frustration in the West with the course of the bombing campaign: As debate mounted about the possible need for ground forces, the envoys felt the pressure from governments, especially in Germany and Italy, to reach a diplomatic solution.

"All this made the participants move faster, because everybody understood that we were on the verge of a big war, an all-European war for sure," Sergeyev said.

The trio made a final push at a dacha outside Moscow that was the favored residence of Soviet dictator Josef Stalin. As they sought to reconcile their positions, they even placed an empty chair at their table -- representing Milosevic -- to which they would turn when they reached a key question that only he could answer.

But among the allies, trust in Chernomyrdin was fading rapidly. He had traveled to Belgrade four times and produced no signs that Milosevic was taking NATO's demands seriously. Doubts grew that he was properly conveying NATO's bottom line conditions: All Serbian forces must withdraw from Kosovo and an international peacekeeping presence, with NATO soldiers at its core, must be allowed into the province to ensure security for returning refugees.

Instead, Chernomyrdin was defending Serbian demands with increasing tenacity. He insisted that since there were about 8,000 patrimonial sites that would each require protection by a minimum of three soldiers, at least 24,000 Yugoslav troops must be allowed to remain in Kosovo. He also rejected NATO's demand that all Serbian forces must leave, since the West had agreed that Kosovo should remain under Serbian sovereignty. And Chernomyrdin said a security vacuum left by departing Serbs would help the rebels of the Kosovo Liberation Army (KLA).

The United States and European allies implored Ahtisaari to make his own trip to Belgrade to spell out Western demands, but he refused to go unless Russia moved closer to NATO's positions. He told German officials that he was determined to avoid shuttling "like a fool on a senseless and doomed mission" and would travel only once, at most twice, to Belgrade to secure an agreement.

On May 26, Chernomyrdin made his penultimate trip to Belgrade and held nine hours of talks with Milosevic. His departure from the Yugoslav capital was followed by one of the heaviest nights of NATO bombing, leading residents to joke darkly that the surest result of a Chernomyrdin visit was a night in the bomb shelters.

He returned to Moscow this time saying he was satisfied that the Yugoslav leader now seemed prepared to accept the G-8 principles. But that declaration only highlighted Belgrade's persistent refusal to withdraw all forces and accept NATO troops on its soil -- positions Chernomyrdin continued to uphold.

Shifting Fortunes

While Russia and the West sparred over NATO's role in a future peacekeeping force, a sudden change in military fortunes on the ground escalated pressure on Belgrade. For weeks, NATO warplanes had enjoyed air supremacy but had failed to dislodge Yugoslav forces who were hunkered down and scattered across Kosovo as they preserved precious fuel supplies.

But a new offensive by KLA forces, thrusting into Kosovo from strongholds along the Albanian border, flushed out many Yugoslav forces hidden around Mount Pastrik. NATO A-10 Warthog tank killers and AC-130 Spectre gunships inflicted a terrible toll on the exposed Serbian tanks, artillery and soldiers.

There were signs that Belgrade was feeling the heat. Citing "deep, deep" intelligence sources, a senior NATO official said the Yugoslav leader had been losing his temper in his office, screaming at aides and throwing military documents into the air in despair. Although a senior CIA official said Tuesday there was no sign that Milosevic had lost his "core belief" that NATO would falter before he would, German intelligence sources said there were signs that the KLA gains had been troubling Milosevic for the past two weeks.

Last Sunday, according to officials, Yeltsin finally stepped into the fray. He ordered Chernomyrdin and Ivanov to come up with a new strategy that would square the circle. "Yeltsin said `fix it,' but the question all along has been `how?' What would be an acceptable fix?" said a senior Western diplomat.

On Monday, Prime Minister Sergei Stepashin called Clinton and declared that Russia wanted to find a way to settle all differences with NATO. U.S. officials said it was clear that Yeltsin wanted to salvage his relationship with the West, particularly before the G-8 summit meeting on June 18-20 in Cologne, where he is expected to seek new economic aid for his battered economy.

"He's invested a tremendous amount in building ties to Western institutions," said a Western diplomat in Moscow. "Sooner or later he was going to find a way to pursue that strategic interest."


When Chernomyrdin joined Talbott and Ahtisaari for their final round of talks at the German government guest house outside Bonn last Tuesday afternoon, the Americans were hoping for a resolution that would send the two envoys to Belgrade for the ultimate showdown with Milosevic.

But the Russians stuck to their guns. Russian military advisers accompanying Chernomyrdin were clearly unhappy about ceding any ground to NATO by putting the alliance at the core of a Kosovo peacekeeping force. Chernomyrdin's aide, Sergeyev, said the marathon discussions were necessary to persuade the Americans that there were serious problems for any Yugoslav withdrawal unless NATO first suspended the bombings.

The envoys toiled past midnight, with Talbott breaking off several times to call the White House. Near dawn, they realized they would not resolve the command problem to Russia's satisfaction and made the issue a footnote in the document.

By morning, when matters looked bleakest, Chernomyrdin appeared to have received fresh instructions -- presumably from Yeltsin's office -- to hammer out an agreement and go to Belgrade.

"There were still some issues left unresolved, but everybody realized it was best to get Chernomyrdin and Ahtisaari off to Belgrade before the sun set," said a senior German official who was closely involved in the talks. "We had to get Milosevic to commit himself on pulling out all of his troops and letting in a NATO-led peacekeeping force. It was none of his business to deal with command problems, and we figured we could settle those later with the Russians."

Once in Belgrade, Ahtisaari read out the two-page document line by line during a 4 1/2-hour meeting with Milosevic and his associates. He would say later that reading the document aloud, with Chernomyrdin by his side, was necessary to make Milosevic realize that they represented "a united front" between Russia and the West.

After answering all questions, and insisting this was the best offer Milosevic would get, Ahtisaari advised him to talk over the terms with members of his government and give him an answer the following day. The next morning, the Yugoslav parliament rubber-stamped its approval, and Ahtisaari was summoned to receive formal approval at Milosevic's office.

In Bonn, Talbott received a phone call from Chernomyrdin with the news that the Yugoslavs had accepted "our document." Talbott was characteristically cautious, even after he was assured that the text included the word "all" when referring to troops to be withdrawn from Kosovo. "Every word, Viktor Stepanovich?" he asked, calling Chernomyrdin by his first and middle names. The Russian replied affirmatively.

Ahtisaari was greeted at the airport in Germany by Talbott, and the two men held a hurried debriefing in the Finn's limousine. Talbott then went to his own car and reported back to Clinton, Albright and National Security Adviser Samuel R. "Sandy" Berger in a four-way conference call.

At the State Department, Albright forbade any premature celebration and cut off talk of the war in the past tense. "I don't want to hear any talk that we have achieved our objective," she said. "We have a lot of humanitarian work to do."

Meanwhile, at the White House, there was grim recognition of the mammoth tasks that lay ahead. When James Dobbins, the State Department's senior Kosovo adviser, clasped his hand on Berger's shoulder to convey congratulations, Berger recoiled. "Let's congratulate ourselves when it's really over," he said.

Correspondent David Hoffman in Moscow and staff writer Thomas W. Lippman in Washington contributed to this report.

CAPTION: Martti Ahtisaari

CAPTION: Viktor Chernomyrdin

CAPTION: Slobodan Milosevic

CAPTION: Strobe Talbott

CAPTION: Igor Ivanov