After Slobodan Milosevic was plucked from his Belgrade jail cell to exchange it for one in The Hague, he left behind him many frightened men in Yugoslavia and the Bosnian Serb Republic.

Could it be, people ask, that Dr Karadzic in particular knows too many secrets

These undoubtedly include his five Yugoslav co-accused on the Kosovo indictment.

But what of the two men indicted for genocide over the worst single atrocity in Europe since the end of World War II?

They are Radovan Karadzic, the former Bosnian Serb president, and Ratko Mladic, his former military commander.

Karadzic has been on the run for years

The atrocity was Srebrenica in 1995, when Mladic's troops rounded up thousands of the town's male population and bussed them to killing fields scattered around eastern Bosnia.

During the intervening years both accused have been enjoying a quiet, if furtive, retirement: General Mladic in Belgrade, Mr Karadzic right under the noses of international peackeepers in Bosnia.

West's reluctance

When Nato peacekeepers first arrived in Bosnia, diplomats worried that arresting the two would provoke a furious Serb backlash, destroying the Dayton peace accord.

Dr Karadzic was also flush with money from a corrupt three-year rule, and able to surround himself with a substantial guard.

The Americans, in particular, were thought unwilling to do anything which would risk casualties, either in the initial snatch operation or in managing the Serb reaction to it.

Srebrenica: Europe's worst atrocity for 50 years

Today, though, S-For - as the peacekeeping force is known - is well entrenched and Dr Karadzic is believed to have a much smaller group of loyal bodyguards at his command than when he left office.

This is where the conspiracy theories start.

Could it be, people ask, that Dr Karadzic in particular knows too many secrets about international dealings with the Bosnian Serb Republic?

He is said to be hiding out near Foca, in eastern Bosnia, which is in the French sector.

Of all Western countries, France has always been seen as most sympathetic to the Serb cause.

Right at the end of the Bosnian war, too, Dr Karadzic and General Mladic arranged for the release, unharmed, of a French pilot they had been holding.

British troops were also allowed to retreat from Gorazde, the other Muslim-held enclave in eastern Bosnia declared by the UN to be a "safe area".

Did the Bosnian Serbs think they had been given the green light to over-run these isolated pockets of Bosnian Government territory to "tidy up the map" before peace negotiations got under way?

Elusive suspect

Perhaps Western governments could not have known what would happen when Gorazde and Srebrenica fell.

But then again perhaps a trial of Dr Karadzic and General Mladic might reveal the contrary.

However, it may be that Dr Karadzic is just hard to find.

Mladic: Now said to be ill

He has given no media interviews for several years (one puported interview to a Bosnian Croat magazine was exposed as a fake) and is said to communicate by letter, fearing that phone calls will be intercepted, giving away his location.

General Mladic is reported to have left Belgrade to take refuge in the mountains of Montenegro, Yugoslavia's junior republic, and is anyway said to be a sick man.

Newspaper reports say that the British Government has offered to carry out an operation to snatch the two using the SAS.

Officials never comment on such claims, but the SAS has been used in the past to apprehend other Bosnian Serbs wanted by The Hague.

Dr Karadzic has the option of doing what his successor in the Bosnian Serb presidency, Biljana Plavsic, did and surrendering voluntarily.

He might then offer to bargain his testimony against Mr Milosevic in return for a lighter sentence.

Dilemma

Mr Milosevic is charged with crimes in Kosovo as well as Bosnia and Croatia.

Western troops were reluctant to snatch suspects

That would present the international war crimes tribunal with a dilemma when it comes to Dr Karadzic and Mr Milosevic - who should testify against whom, who should be induced to rat first?

On the one hand, Mr Milosevic is their biggest catch, former head of an internationally-recognised state, and allegedly the ultimate author of much of the mayhem which led to some 300,000 deaths in the wars of Yugoslavia's break-up.

He was, notoriously, a leader who signed few documents, who carried out decisions in small face-to-face meetings.

The testimony of former closer associates will be vital to establish the link between well-documented atrocities on the ground and orders given in Belgrade.

But on the other hand, Dr Karadzic was the political figure in charge of the Bosnian Serb Republic during the genocide committed in Srebrenica.

Whatever evidence he might have to offer, how could the tribual be seen to bargain over charges involving an atrocity of such magnitude?

Mr Milosevic would surely have secrets to tell about what happened there.

Time short

If Dr Karadzic is thinking of offering himself and his testimony, he may have to hurry.

The extradition of Mr Milosevic shows how things have changed in the Balkans.

The former Yugoslav president himself was reportedly left bewildered by the speed with which he found himself in the hands of the international war crimes tribunal.

In Belgrade, it has been reported that others in his close circle want to do a deal with The Hague.

For Dr Karadzic, time may be running out.