The co-ordination of the international community in the Balkans has been thrown into confusion by revelations that the leader of Macedonia's rebel army was a leading figure in Kosovo's UN-funded civil defence force.
Before launching war in Macedonia, Commander Gezim Ostremi was paid by the UN to help set up the Kosovo Protection Corps (KPC), being appointed its chief-of-staff.
Now President Bush has banned Commander Ostremi from entry to the US, and accused five key members of the KPC of aiding the rebels.
Yet the United Nations says it will take no action against these five men, all still serving officers, because Washington has yet to pass on details of what the men are supposed to have done.
This row comes just as the US and the EU are groping for a joint response to the escalating violence in Macedonia, which yesterday saw rebels fighting government forces in several places in the northern mountains.
Yet while one part of NATO tries to stop the guerrillas crossing the border from neighbouring Kosovo, in Kosovo itself other parts of NATO and the UN are busy paying and training them.
The KPC, formed at the end of the Kosovo war as part of a deal between the former guerrillas of the Kosovo Liberation Army and the UN. In return for the guerrillas disbanding, they would be allowed to reform, a new force, funded and trained by the UN but organised for civil defence.
In fact, the KPC's role is a polite fiction. Because Kosovo is still officially part of Yugoslavia, it can have no army. Yet Kosovo's Albanian majority are keen to have an embryonic army to protect them should NATO ever withdraw. The result is an awkward compromise. The KPC is an army without weapons which trains for war, but pledges publicly that its job is limited to fight forest fires and natural disasters.
Now this delicate balance has been thrown out of gear by evidence that it is feeding men into battle in Macedonia.
The lack of close supervision meant it was weeks before the UN realised Commander Ostremi had left to command the rebels in Macedonia - with some assuming he had gone on holiday.
NATO provides the 5,000strong KPC with training in a wide range of military skills, including transport, communications, map-reading and medicine, though there is a ban on firearms training. The UN pays its $7 million per year wage bill.
Inside Kosovo, the KPC has been a success: Its units, who wear military uniforms, have military ranks and carry out military drills, are well disciplined. Fears that they would carry out revenge attacks against their former Serb enemies have proved groundless.
Washington's blacklist includes not just Commander Ostremi, but his replacement as chief-of-staff at the KPC, Commander Daut Haradinaj.
Also on the list are the commander and deputy commander of the KPC's elite force, the Rapid Reaction Corps, plus the leaders of two of its six regional divisions, Commandrer Sami Lushtaku and Commander Mustafa Rrustem.
In a statement last Friday President Bush said the US would restrict entry of these men for seeking to "undermine peace and stability in the region" as well as those "responsible for wartime atrocities". He did not specify who is blamed for which offence, but said the move aimed to cut fund-raising in the US for such groups.
Commander Rrustem yesterday said he was mystified by the American decision to ban him. "I have no information about this. We read about it in the newspapers, we are not accused of anything."
He denied having involvement in the war in Macedonia. "Maybe some people want to go and help them [the Macedonians]. There are links from ancient time. But for us what is important is the KPC."
Commander Rrustem, known as "Remi" earned fame during the Kosovo war as one of the most successful guerrilla commanders. He has since become a favourite with NATO commanders, whose glowing commendations line the walls of his office.
Certainly if the Americans have reservations about him they have yet to show it: on Tuesday two separate US army teams came to his base to train his men.
A KPC spokesman, Mr Shemsi Syla, said Commander Ostremi is no longer a member, but denied he had been sacked. "Our regulations say that you are no longer a member of the KPC if you fail to report for work. Ostremi has not reported for work for some time."