Slobodan Milosevic was still riding high a year ago as the president of Serb-led Yugoslavia, labeling domestic critics "NATO lackeys and traitors" and spitting defiance at Western governments. Prospects for his removal from office, let alone for his transfer to an international tribunal on war crimes charges, seemed remote.

But then Milosevic, whose skills at political maneuvering had become legendary in the Balkans, made a fundamental tactical mistake that ultimately brought him down. Convinced that the political opposition was too weak and fractured to represent a serious challenge, he entrusted his fate to the voters, deciding last July to call presidential elections a year before he was required to do so by the Yugoslav constitution.

To almost everyone's surprise, and with the help of American "pro-democracy assistance" amounting to tens of millions of dollars, the opposition overcame its divisions and won elections held Sept. 24. Even more remarkable, the anti-Milosevic coalition ensured that election results stuck by organizing a peaceful street uprising that deprived Milosevic of support from the security forces that constituted his last bastion of power.

But beyond these tactical mistakes -- and Milosevic's hubris in assuming that the Serbian people would support him forever -- were even larger strategic miscalculations that go back to his rise to power in the late 1980s. Like other Communist politicians, particularly from the Balkans, Milosevic chose to remake himself as a nationalist, swapping a bankrupt ideology for an ideology that, at least for a time, was capable of mobilizing millions of people.

In Milosevic's case, according to allies and opponents alike, the transformation from Communist to nationalist was almost entirely cynical. From the beginning, when he bathed in ecstatic applause from the embattled Serb minority in Kosovo in 1989 by promising that "no one will ever dare beat you again," Milosevic viewed the nationalist card as a device for achieving power.

At first, nationalism seemed an attractive option to many Serbs, the largest single nationality in the six-republic Yugoslav federation built by Tito out of the rubble of World War II. With other South Slav ethnic groups, including Croats and Slovenes, pushing ahead with plans for separation from Yugoslavia, Serbs began to feel a growing sense of grievance, compounded by memories of wartime atrocities at the hands of pro-Hitler Croatian fascists. Milosevic's slogan -- "Serbs have the right to live in a single state" -- became a potent rallying cry.

But after initial successes -- at one point Serbian forces controlled one-quarter of neighboring Croatia and two-thirds of Bosnia -- hard-line nationalism began to exhaust itself. The Serbs experienced a series of military defeats in Croatia and Bosnia. Finally, they suffered a dramatic defeat in their own, largely ethnic Albanian-inhabited province of Kosovo. A 2 1/2-month NATO bombing campaign ended in June 1999 with hundreds of thousands of Serbs fleeing a region that had been depicted by Milosevic's propaganda machine as the birthplace of the Serbian nation.

Equally important was the economic devastation wrought by almost a decade of strife and the Milosevic government's refusal to introduce serious economic reforms. Once envied by the citizens of neighboring communist countries for their relative affluence, Serbs saw their standard of living plummet under Milosevic. While Hungarians, Czechs and even Bulgarians began to find a way out of the economic crisis that resulted from communism's collapse in 1989, Serbs descended deeper and deeper into penury and international isolation.

This sense that Serbs could never find a way out of the economic morass as long as Milosevic remained in power probably was the single largest factor in his election defeat last September. The opposition candidate, a mild-mannered constitutional lawyer named Vojislav Kostunica, bested Milosevic at the polls by promising Serbian voters nothing more -- and nothing less -- than "a normal life in a normal country."

Economic reasons also were an important factor in the Serbian government's decision to extradite Milosevic to face war crimes charges in The Hague. The decision came, with surprising swiftness, on the eve of an international donor conference that could unlock up to $1 billion in funds for the rump Yugoslavia that now comprises only Serbia and Montenegro. After initially dragging their feet on the demands for Milosevic's transfer to The Hague, Serbian leaders finally came to understand that his extradition was an essential first step to economic recovery.

Of all Milosevic's strategic miscalculations, perhaps the most serious was his failure to anticipate post-Cold War realities. Unlike his fellow Communist turned nationalist, the late Franjo Tudjman of Croatia, Milosevic demonstratively turned his back on the West. While Tudjman curried favor with Western governments, Milosevic viewed Western leaders with disdain and believed they would never challenge him in his own back yard.

At first, Milosevic's defiance of the West appeared to be a shrewd political move. Neither the United States nor the European Union had much appetite for intervening in obscure Balkan conflicts. The Serbs acted with little to fear from the outside in Croatia and then in Bosnia. Milosevic's contempt for Western politicians seemed well founded.

But as war spread from one part of the former Yugoslavia to another, and the number of killings and refugees became too great to ignore, Western policy toward the Balkans underwent a fundamental change. In 1995, at the height of Serbian military successes in Bosnia, Western governments gave tacit approval to Croatian forces to mount a crushing counteroffensive. A NATO bombing campaign against Serbian targets in Bosnia and a burst of U.S. diplomacy laid the groundwork for the November 1995 Dayton peace agreement.

During and after the Dayton negotiations, U.S. officials tended to view Milosevic as an indispensable interlocutor and ally in restoring peace to the Balkans. Little thought was given to encouraging his removal from office. It was not until the showdown over Kosovo in early 1999, when Milosevic defied a NATO ultimatum to accept a Western-led peacekeeping force to separate Serbs and ethnic Albanians, that Washington began to perceive the Yugoslav president as part of the problem and not part of the solution.

When Serbian democracy activists took to the streets of Belgrade in December 1996 to protest the manipulation of local government elections by Milosevic's ruling Socialist Party, they met with little encouragement from the West. By contrast, three years later, after the Kosovo crisis, the United States poured millions of dollars into a determined effort to unseat the Serbian ruler.

Supporters of ex-president Slobodan Milosevic attack a car during a demonstration in Republic Square in Belgrade.