Some historical events are no accident and the timing of Radovan Karadzic's arrest is one of them. It comes just days after the formation of a pro-western government in Belgrade, and in the midst of a purge of Serbia's security chiefs suspected of protecting war criminals. The arrest also took place just before a foreign ministers' meeting in Brussels -- and the European Union has made the capture of Karadzic and his former military commander, Ratko Mladic, a condition of membership. The new government and EU pressure explain why it happened now.

In the end, the man responsible for the Srebrenica massacre was caught on a local bus in a suburb of Belgrade. Indeed, he was so confident of his disguise and new identity, a specialist in alternative medicine called Dragan Dabic, that he moved freely around the city without bodyguards. Without question, this shows that Karadzic must have been protected by the Serbian security services that claimed to be hunting for him for much of the last decade.

Karadzic's arrest is a coup for the EU's policy of soft power, an effort to change the behaviour of a country through gentle inducements as well as force. How long his former henchman Mladic now survives on the run remains to be seen.

Karadzic's arrest also came just in time for the international war crimes tribunal in The Hague, which was due to close in two years' time in a cloud of futility. Karadzic's mentor Slobodan Milosevic died in custody two years ago, having ground proceedings to a virtual halt by conducting his own defence and making a mockery of the trial.

Karadzic's prosecutors and judges are unlikely to make the same mistake. They will deliver swifter justice. They will be able to do so in part because the case against Karadzic is simpler than it was against Milosevic. It is an established legal fact that Serbian forces under his command committed genocide against the Muslims of Srebrenica in July 1995. Karadzic and Mladic were the two masterminds of the campaign of terror and ethnic cleansing aimed at purging half of Bosnia of non-Serbs.

The war in Bosnia from 1992-95 has fallen from prominence in the narrative of modern conflict. It is yesterday's news and each year there are more threatening conflicts and fresher wounds. But we forget at our peril the enormous human cost which the attempt to create a "Greater Serbia" exacted, before it was finally extinguished" -- 100,000 people killed and over two million forced from their homes.

Justice will help Bosnia and Serbia to recover. Karadzic, warlord, poet, psychiatrist and gambler, thought he could outsmart the war crimes tribunal by lying low for long enough until the political will of the international community was exhausted and the court was disbanded. He almost succeeded.