Neither could the Bosnian Serbs–whose brinkman-ship has repeatedly reduced the mighty Western Alliance to feckless threats and weak reprisals. All that changed last week, when NATO, led by American fighter planes, launched its most massive military operation even In the first wave, U.S. F-15E’s, F-10s and F/A-18s took off before 2 a.m. local time from the USS Theodore Roosevelt in the Adriatic and the Aviano air base in Italy, and joined a fleet of European radar-suppression and attack aircraft. Their target: Serb air-defense systems to the south in Mostar, to the north near Tuzla and as far east as Gorazde (map). In subsequent waves, the allies went after command and control centers, ammunition dumps and surface-to-air missile sites; A-10 Warthogs and AC-130 gunships pounded heavy-artillery installations around Sarajevo. And from the west, British, French and Dutch members of the Rapid Reaction Force unloaded more than 1,000 shells from their big guns on Serb emplacements ringing the capital.

Over three days, the allies flew more than 500 sorties. They hit a radar installation at Foca, telephone relays and a radar installation near the Bosnian Serb headquarters in Pale and a huge ammunition factory at Vogosca. The West got off nearly unscathed: a Serb SA-7 shoulder-fired missile brought down a French Mirage 2000 jet; the pilots apparently parachuted to safety. On Friday, NATO and the United Nations called a temporary halt to the air campaign to “assess” the situation. The result was not as devastating as the Pentagon hoped. NEWSWEEK has learned that the allies–hampered by bad weather and what a senior NATO official calls “inappropriate” fighter jets too swift to loiter over their targets–had to go back two and three times to take out or damage 90 military sites, a kill rate of less than 50 percent. “It’s been incredibly disappointing,” says the official. “The air force has had this target list for three years; it’s amateur city.”

But the attack seemed to impress the Bosnian Serbs. Only hours after the lull in allied bombing, they agreed to sit down and negotiate this week in Geneva–and to accept as a starting point a U.S.-backed plan to leave the Serbs with less than half of Bosnia. Under pressure from the United States, NATO threatened to resume its at-tack if the Serbs failed to move their heavy weapons out of range. end assaults on “safe” areas in Bosnia, and open routes and restore water and electricity to Sarajevo. In the course of half a week, the West moved closer to a goal that had eluded it for 40 months–shutting down a hideous conflict that has cost more than 200,000 lives. The allies’ strategy: to wage war in order to make peace.

What shaped this radical turn of events? Mostly American determination to take the lead–and changing conditions on the ground. Last month’s Croatian offensive in the Krajina region and western Bosnia surprised and weakened Serb forces. The coup de grace came from Serbian President Slobodan Milosevic who, despite repeated promises of assistance, declined to help his ethnic cousins when they most needed it. Having thrown over communism, nationalism and the dream of Greater Serbia, Milosevic eventually decided to hang his political future on cooperation with the West.

Bill Clinton didn’t want Bosnia in his political future either-and resolved in July to take decisive action. The COP Congress decried his Balkan policy. After the humiliating display of U.N. hostages handcuffed to strategic Serb sites, and the brutal conquest of two Muslim safe areas, COP leaders voted to lift the arms embargo against the Bosnians. That would ultimately have forced Clinton to send U.S. troops–a politically disastrous move.

The president’s frustrations boiled over one humid evening in July on the private putting green in back of the White House. Clinton, says a top aide, demanded a progress report on the Balkans, saving, “The status quo in Bosnia is unacceptable,” and then angrily flubbed several shots. Days later, an Oval Office meeting with Clinton’s foreign-policy team produced poignancy, but little sharpening of purpose. Srebrenica had just fallen, and U.S. officials seemed haunted by reports of Serb atrocities. Vice President Al Gore, says a senior official, was particularly appalled by the picture of a young Muslim woman who fled into the woods and hanged herself. “My daughter asked me the other day why we weren’t doing something about it,” Gore said. None of the assembled had an answer. “Everyone around the room was very, very quiet, says the administration official.

After more than three years of half measures, Clinton had few options left–except to take charge. Madeleine Albright, U.S. ambassador to the United Nations, drove home the point. NEWSWEEK has learned that she sent a memo to the president arguing that the time had come for U.S. leader-ship–and that the administration should develop a plan that would strongly support the Bosnians if the Serbs proved inflexible. National-security adviser Tony Lake had the germ of a plan in his idea for diplomacy backed by force, a doctrine he had been devising for more than a year. Working with senior foreign-policy officials–including the three U.S. negotiators who later died in a road accident outside Sarajevo–Lake came up with a two-pronged strategy: the vigorous pursuit of a settlement, backed up by an aggressive military operation. “You can’t have peace in Bosnia without the threat of war,” says a senior U.S. official.

The diplomatic side of the plan proposed to:

lift the trade embargo on Serbia in exchange for recognizing Bosnia and Croatia;

maintain a single Bosnian state, with separate Serb and Croat-Muslim governments and a loose central authority;

give economic assistance and NATO enforcement of a settlement to the Bosnians, if they negotiate in good faith;

offer the Croats eventual membership in the Partnership for Peace. The war scenario envisioned a massive NATO bombing campaign against the Bosnian Serbs and a multilateral effort to arm and train the Muslims. The main U.S. challenge was convincing the Europeans. France and Britain were finally coming round to the idea of a tougher stance against the Serbs. But the allies had shot down almost every past U.S. initiative. This time, Clinton took a different tack: he wasn’t asking for advice from foreign leaders; he wanted their support for his plan. “There was a tacit message–you better be with us,” says a senior U.S. official. In early August, the president sent Lake and his team on a low-key, weeklong mission to various European capitals–but first gave him some classic tips on salesmanship. He encouraged Lake to tighten his 40-minute pitch, saying, “Give them the message, give them the details and then reinforce the message in the close,” the official told NEWSWEEK. Lake’s mission succeeded. The deaths of the U.S. negotiating team members only redoubled administration efforts; one of the widows pleaded with officials, “Please end this thing.” The West waited for the right moment to try. its dual strategy–and found it in last week’s massacre in Sarajevo.

As allied bombs were dropping on Serb-held Bosnia, U.S. negotiators made a risky approach to Serbia. Assistant Secretary of State Richard Holbrooke, who led the team, didn’t know what kind of reception he’d get from Milosevic. “It’s really terrible, these airstrikes. You really ought to stop it,” the Serbian president said, smirking. “Now, let’s talk business.” Business turned out to be a new agreement signed by Bosnian Serb leaders, authorizing Milosevic to negotiate on behalf of all Serb parties. “This was the procedural breakthrough we’ve been awaiting for 16 months,” says Helbrooke. No wonder he hurried the announcement of this week’s Geneva conference: Holbrooke was determined to lock the Serbian president into a public commitment to negotiations.

The war is far from over. At the weekend the Bosnian Serbs hadn’t pulled back their artillery–and the allies stood ready to resume bombing. Despite U.S. warnings, the Muslims refused to rule out military offensives under NATO cover. And Milosevic has proved untrustworthy before. “It’s so hard to believe that anything you do in Bosnia can come out well,” says a senior U.S. official. It’s always easy to be pessimistic about the Balkan war–but last week, for once, it was possible to be hopeful.

Last week’s shelling of Sarajevo’s marketplace left 37 dead and more than 80 wounded, precipitating the largest NATO airstrikes ever. U.S., French, British, Spanish and Dutch planes all took part in the attack.

1 At 2 a.m. Aug. 30 the first wave of aircraft take off in the dark from NATO bases in Italy and the USS Theodore Roosevelt. They bomb Serbian air-defense installations from Mostar to Gorazde to Tuzla.

2 A second wave of F-18 and F-16 fighters and radar-jamming planes target ammunition depots and Serb command posts near

3 French. British and Dutch troops of the U.N.’s Rapid Reaction Force, stationed on Mount. Igman, fire more than 1,000 shells on Serb positions around Sarajevo.

4 Succeeding waves on Aug. 30 target Serb command posts and ammunition depots. NATO suspends bombing to look for French pilots shot down near Pale.

5 On Aug. 31, NATO warplanes continue to strike targets around Sarajevo, hitting at least two ammunition dumps. Bad weather and low clouds prevent wider attacks. On Sept. 1, NATO agrees to temporarily suspend attacks to give Serbs the opportunity to meet the international community’s demands.

Some of the 250 aircraft used in last week’s NATO bombings in Bosnia.

United States 20 F-16s, 2 AC-130 Warthog gunships, 8 O/A-10 Thunderbolt attack planes and FA-18C Hornet fighters.

France 5 Mirage 2000C fighters, 5 Jaguar and $ Mirage 2000K/D attack planes.

United Kingdom 6 GR-7 Harrier attack planes. 6 Sea Harriers.

Spain 8 EF-18A Hornet fighters. Also air support and air-to-air refueling.

Netherlands 7 F-16A attack planes.