Karadzic and Mladic were the Bosnian Serbs' wartime leaders
The two most wanted men in the Balkans may not be too well hidden to be captured, but too well protected, writes the BBC's Nick Thorpe.
"Look, isn't that your friend?"
The Dutch journalist's wife pointed through the glass window of the restaurant at a man sitting at an outside table.
Even from behind, the shape of the head and the greying salt-and-pepper mop of hair of one of the world's most wanted men was easily recognisable.
And when he turned his head in profile, the journalist was absolutely sure.
Radovan Karadzic was drinking coffee at a remote restaurant on the Foca to Gacko road in southern Bosnia.
It was April 2005.
A short while later, a nervous looking Karadzic and his female companion got up suddenly and left in a red Mercedes.
Getting too close to Karadzic could cost a journalist his life, it seems
Placing the interests of justice before those of his own fame and fortune, the journalist contacted the International War Crimes Tribunal.
The story leaked soon afterwards. The Tribunal blamed the police.
Then the police blamed the International High Representative in Bosnia, Paddy Ashdown, for the disclosure.
After that, the journalist felt it was time to write his own story, under another name.
But first he made contact with Dutch military intelligence, to find out if there had been any follow-up to his information.
"Don't write about it, if you value your life," he was told, to his amazement.
"Several of our agents visited the restaurant. On their return to the Netherlands, they needed protection."
Such is the power, allegedly, of the mafia ring which protects the former Bosnian Serb leader.
The story dovetails neatly with another which appeared recently in the Bosnian newspaper, Slobodna Bosna.
Radomir Ceranic, a senior employee of the Bosnian secret service, OSA, described the alleged murder of two CIA agents by Karadzic's men when they got too close to him.
Their car and the tracking equipment they used was discovered.
The bodies of the CIA men, both US citizens, were never found.
Ceranic had just been fired from his job, so he may have borne a grudge. Whatever the truth, it is another hint of the power and ruthlessness of Karadzic's network.
So I asked well-informed sources in Bosnia and Serbia, if the arrest of Stojan Zupljanin, a former Bosnian Serb police chief and wartime adviser to Karadzic, three weeks ago, was a sign that the net is finally closing in on Karadzic and his military commander, Ratko Mladic?
Or was he just a lamb, sacrificed to smooth the creases in a power-sharing agreement between the Democratic Party and the Socialists in Belgrade, as they cobble together a new Serbian government?
"A lamb," came a chorus of replies. "They'll never touch the big two."
Ratko Mladic is still a hero for Serb ultra-nationalists
There was a time in the early 1990s, before he started his war to prove that people of different cultural backgrounds cannot live together, when I interviewed Radovan Karadzic regularly, whenever I was in Sarajevo.
But I soon got bored by his answers. We never seemed to get beyond 1941, and his obsession with the murder of huge numbers of Serbs at the Jasenovac concentration camp in Croatia.
So I preferred to talk to Milorad Ekmecic, a professor of history at Sarajevo University, and the eminence grise behind Karadzic's party.
With Ekmecic we could at least talk about the present, and the party's brutally frank plans to create great swathes of "ethnically pure" Serb territory in Bosnia, based on the results of the 1991 census.
"We Serbs have to be exclusive," the professor insisted, "in order to survive."
'No political will'
Some years ago, I set out through the Serbian Republic in Bosnia.
The forestry workers at the bar hardly give him a second glance. They have seen him so many times before. He is with his wife, and the owner of the restaurant
We have heard from the victims of war crimes, I thought. Now let us hear from the perpetrators.
But I deliberately left Karadzic and Mladic out.
And focused instead on men convicted by the Hague Tribunal and released after serving jail terms. And on other war crimes suspects, still on the run.
It was not particularly hard to find them. But I could not help hearing whispers about the terrible twins, Mladic and Karadzic.
The word was, that Western intelligence agencies knew roughly where they were, but that there was no political will in London or Washington to risk the lives of British, or US agents, in a bid to seize them.
Time passes. My new map of the Balkans does not even list a town called Foca.
It is there under the name Karadzic's men called it, after they drove out or killed its Moslem inhabitants: Srbinje.
And 38km (24 miles) down the road, on the edge of the Sutjeska national park, Radovan Karadzic has just got out of a red Mercedes.
The forestry workers at the bar hardly give him a second glance. They have seen him so many times before. He is with his wife, and the owner of the restaurant.
"Look - isn't that your friend, sitting over there?" asked the Dutch journalist's wife.
From Our Own Correspondent was broadcast on Saturday, 28 June, 2008 at 1130 BST on BBC Radio 4. Please check the programme schedules for World Service transmission times.