Radovan Karadzic's fate was sealed when influential Serb nationalists opposed to the war crimes tribunal in The Hague were replaced systematically in the security services by liberals loyal to the pro-EU President of Serbia, Boris Tadic.

Mr Tadic was first elected President in 2004 and immediately began making key personnel changes to Serbia's powerful Army and police force, including the internal security service the BIA, the agency believed to have given Dr Karadzic his new identity in 1998.

However, he had to wait until voters rejected the increasingly nationalistic Prime Minister, Vojislav Kostunica, in elections in May before completing his sweep.

The rewards were instant: the fourth-most-wanted war crimes suspect, Stojan Zupljanin, was arrested on June 11 after 13 years on the run, and Dr Karadzic, one of the remaining three, was arrested last week.

Stefan Wolff, Professor of Political Science at the University of Nottingham and a Balkans expert, said: “We now have a pro-European President and a pro-European Government and to their credit they took responsibility and showed real leadership, making the direction of the country clear.

“There has also been enough turnover in the pro-Milosevic security agencies that those with links to the past are either out or more concerned with looking after themselves.”

Mr Tadic, 50, was born in Sarajevo, the Bosnian capital torn apart by Serb forces under the political leadership of Dr Karadzic in the siege of 1992-95, which left 12,000 dead.

He became leader of the pro-Western Democratic Party in 2004 after the assassination of Zoran Djindjic in retaliation for the arrest of Slobodan Milosevic, the wartime Serb President who died in his cell at the International Criminal Tribunal for the former Yugoslavia in The Hague.

Although hamstrung by the influence of Mr Kostunica in his first term, Mr Tadic ensured two key appointments in 2005: Rasim Ljajic became head of the National Council for Co-operation with the International Criminal Tribunal and Vladimir Vukcevic was appointed war crimes prosecutor.

Mr Ljajic, 44, a staunch believer in a multi-ethnic Serbia with a passionate desire to see justice done for those who led it into war, leads a small Muslim party that has become an important component of the coalition that took office after the May elections.

Mr Vukcevic has vowed to pursue war crimes suspects “until the job is done” despite receiving numerous death threats as more fugitives are brought to justice both in The Hague and in the Serbian courts. Last month he secured the conviction of Radomir Markovic, Mr Milosevic's security chief, for organising an assassination attempt on Vuk Draskovic, a former opposition leader, in a staged road accident in 1999.

Mr Tadic, an advocate of Serbian co-operation with Nato despite the bombing campaign which targeted buildings in Belgrade in 1999, moved in 2006 to install a new army chief of staff who shared his pro-Western views. Zdravko Ponos, 45, studied at the Royal College of Defence Studies in London and plans to modernise the Army by ending conscription.

Last year, Mr Tadic secured the role of Defence Minister for Dragan Sutanovac, 40, a close Democratic Party colleague for whom he acted as best man. Mr Tadic, a former college lecturer, likes to surround himself with familiar faces: Vuk Jeremic, the Foreign Minister, studied psychology under the future President.

Mr Ponos and Mr Sutanovac oversee the Military Security Agency (VBA), which is being led by its chief, Svetco Kovac, out of the days of collusion with war crimes suspects.

General Kovac admitted in 2005 that the VBA knew that Ratko Mladic, the Bosnian Serb former general who remains on the run, was living at his home address until 2002, when it allegedly lost track of him, showing the complicity of the Army in looking after one of its own.

By some accounts, the VBA was the service that first located Dr Karadzic in his guise as Dragan Dabic and handed over surveillance to the BIA to make the arrest.

The BIA has long been suspected of helping to shelter Dr Karadzic and, despite being switched to government oversight several years ago, remained in the grip of nationalists until the new Government was formed at the end of June. The day after the departure of Mr Kostunica as Prime Minister, his close ally Rade Bulatovic handed in his resignation as head of the BIA, making way for a pro-Tadic replacement.

Mr Bulatovic, who shares a Montenegrin background with Dr Karadzic, would have been in charge when the war crimes fugitive was being followed in his disguise as Dr Dabic but probably did not want to be associated with his capture.

The new head of the BIA, Sasa Vukadinovic, 36, is a known supporter of the Democatic Party and was appointed by Mr Tadic on July 17, only days before agents swooped on Dr Karadzic.

Links to criminals

— The civilian spy agency, known as BIA, emerged after reforms of Serbia’s intelligence organisations in 2000. It is still alleged to have strong links to organised crime

— Rade Bulatovic, who headed the BIA, which is believed to have given Dr Karadzic his new identity, resigned the day after Serbia’s nationalist Prime Minister, Vojislav Kostunica, resigned

— The BIA’s new leader is Sasa Vukadinovic, 36. The extent of his role in Dr Karadzic’s capture is uncertain, since he took on his new job only four days before the fugitive’s arrest

Sources: Times database, BIA

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