The rupture in relations had been ordered by General Ratko Mladic, the Bosnian Serb commander indicted for war crimes, following the arrest by the Bosnian government of two senior Serb officers suspected of massacring civilians. The order was honoured by his minions more in the breach than the observance, and was formally revoked on Saturday night by the civilian Serb leadership, on orders from Belgrade.
Mr Holbrooke, who bludgeoned Bosnia's factions into submission last year, was sent back to the region to cajole the parties into full compliance with Dayton. "I think this is going to get straightened," he said as snow fell on Sarajevo airport. "Admiral Smith [the Nato commander] called it a bump in the road. We agree with him."
After talks with President Slobodan Milosevic of Serbia, Mr Holbrooke is due to return to Sarajevo this morning. According to a US official, his aim in Belgrade was to discuss with Mr Milosevic how best to handle the expected indictment by the international war crimes tribunal of General Djordje Djukic and Colonel Aleksa Krsmanovic, arrested by Bosnian forces on 30 January.
They were visited in jail yesterday by John Shattuck, the State Department's senior human rights official. He said: "The conditions under which they're being held are very much up to international standards. They seem to be being well treated. They had no specific complaints about the conditions. Both of them are receiving medical assistance and one of them was visited by his wife yesterday, as permitted by the court." Four other Serbs detained by the government were released on Saturday night.
Mr Holbrooke said the arrest of suspected war criminals - criticised by some Nato officials as unhelpful to the peace process - did not conflict with implementation of the deal. "Those are both parts of the Dayton agreement," he said.
However, members of Nato's Implementation Force (I-For) are critical of the emphasis placed on war crimes. "Without diminishing the importance of the work of the war crimes tribunal, their moral crusade is premature, because it's very damaging to the peace process," an I-For official said after Gen Djukic's arrest. "It's making things very difficult for us."
That was not the message Mr Holbrooke brought to his meeting with President Alija Izetbegovic of Bosnia. There was no pressure for an early release, said Vice-President Ejup Ganic. "My understanding is that the American government is pleased that we are holding two persons that are accused war criminals. They support us."
I-For has sought to distance itself from the issue of war crimes, despite its mandate to arrest suspects indicted by the tribunal if they cross peace-keepers' path. A Nato spokesman, Lt-Col Mark Rayner, admitted that I-For troops had not been issued with the names or photographs of any of the 51 suspects at large, arguing that this would constitute a "man- hunt".
"If [Nato] comes across them in the natural course of their duty they may detain them if practicable - if they see them, if they recognise them. If they don't, they can't," Col Rayner said yesterday. "If you tell a soldier on one hand that you are not here to hunt down indicted war criminals and on the other hand you give him a photograph which helps him do just that, that would send a confusing message."