It may have won the war - with a little help from NATO - but the Kosovan Liberation Army is rapidly showing itself unfit to govern the peace.
With each passing day, the circumstantial evidence linking the KLA to killings, intimidation, threats and house-burnings continues to grow. Some aid agencies and military sources now talk of an orchestrated campaign of attacks on ethnic Serbs, their houses and their churches.
It's a new form of ethnic cleansing driven by bitterness, a desire for revenge and, arguably, local demand for a Kosovo rid of Serbs.
The best the commander of the Kfor peacekeeping troops in Kosovo, Gen Sir Michael Jackson, could say about the KLA this week was that its leaders did not appear to be in control of the rank-and-file.
But the leadership itself is under suspicion now, especially after the bizarre incident last weekend in which Mr Rexhep Salimi, a KLA leader and self-styled interior minister of an independent Kosovo, pressed a gun to the head of a patrolling British soldier.
"This one's for you," he screamed in Albanian, making as if to press the trigger.
Wiser counsel ultimately prevailed and Mr Salimi was calmed and allowed to go.
But the incident outraged the British, and prompted Gen Jackson to issue a sharp reminder this week that Kfor is the only legitimate security force allowed in Kosovo. He warned the KLA not to create a rival security force.
But this is precisely what the KLA is doing. A core group of 3,000 to 4,000 guerilla fighters is being moulded into a would-be combined state army and police force. The word "Liberation" in Kosovo Liberation Army has been dropped. The organisation's political wing is being strengthened under Mr Hashim Thaci, a man whose nom de guerre was "the snake".
The KLA needs to strike while the iron is hot. Never before has it been so popular with ordinary Kosovans. It played an active part in throwing off the yoke of Serb oppression when pacifist leaders, such as Mr Ibrahim Rugova, were seen to be weak and ineffectual.
Yet, just when it is ready to assume the mantle of power, the West is drawing up its own plans for a democratic, multi-ethnic Kosovo. Elections are not likely for a few years and until then, power will remain firmly in the hands of Kfor and the UN.
KLA impatience is most visible in Mitrovica, where the standoff between the town's Serbs and Albanians continues, with French Kfor troops in the middle. The Albanians, who have been demonstrating daily to be allowed march into the northern quarter, are not all KLA supporters. But no-one doubts that the KLA is using its muscle to put the peace-keepers under pressure.
The French liaison officer in Mitrovica blames the demonstrations on KLA anger that one of its weapons caches had been uncovered. "In some caches we find uniforms and ensigns that lead us to believe that the people involved could be members of the KLA. But in other cases, these outfits belonged to criminals who wanted to pretend they were associated with a military group," he says.
On several occasions this week, the French have fired on armed gangs of Albanians thought to have KLA links.
Tensions are high throughout Kosovo. On Wednesday, US soldiers arrested 10 Albanians after discovering a KLA headquarters in Djilan. In Dobrocane, the US came to the rescue of Russian troops who were under attack from a mob of 500 Albanians.
In the German-controlled sector to the south, Kfor troops regularly find arms caches smuggled in from neighbouring Albania.
Groups of Albanians are systematically looting Serb houses, then setting them on fire. KLA involvement is suspected. Smuggling across the border provides a ready source of income.
The KLA may not be the world's best-known or biggest guerrilla group, but it is certain ly one of the youngest. It's only six years since its first armed attack, when it killed two Serb soldiers in Glogovac, and eight years since the organisation was founded.
The KLA has murky Stalinist and even fascist roots, but most of the present leadership received their grounding in political activism while at Pristina university. Many then spent time in exile, training fighters and raising money among overseas Albanian communities.
International organisations hope to reintegrate former guerrillas into society. The International Organisation of Migration (IOM) says it has registered over 9,000 former combatants for a programme designed to ease them back into civilian life.
"It's important to rehabilitate them now, before they end up fighting again or join the Albanian mafia," says Mr Michael Barton, liaison officer with IOM.
However, cynics doubt the KLA ever had so many members and suggest that those registering are motivated more by a desire for financial handouts than a willingness to lay down arms. With the deadline for the handing in of weapons by the KLA approaching next month, tensions are certain to rise.