With NATO's threat to bomb Yugoslavia if it went back to war in Kosovo exposed this week as a bluff, the West is turning its attention to pressurising the other side in this spiralling conflict, the Kosovo Liberation Army.
The KLA, fighting for an independent state, has been invited with other ethnic Albanian groups to a Vienna conference next week by the Organisation for Security and Co-operation in Europe.
OSCE officials hope that the ethnic Albanians, at loggerheads over whether military action is the way to overthrow Yugoslav rule, will agree a common line for talks next month with the Belgrade government. This is motivated by the conclusion that no amount of NATO pressure on Yugoslavia alone can bring peace to Kosovo.
Western military observers say that attacks by the KLA against Yugoslav targets are often the reason, if not the excuse, for reprisals by the security forces. Some leaders want NATO to go further - threatening military action against the guerrillas. Mr Carl Bildt, the Swedish politician who was international high representative in charge of implementing Bosnia's peace plan three years ago, called earlier this month for NATO to deploy 60,000 troops along the mountainous Kosovo-Albania border to cut KLA supply lines.
Tactically, NATO could do it. In 1995 the alliance deployed a similar force to oversee Bosnia's peace agreement. But therein lies the difference. NATO commanders in Bosnia have an oft-repeated phrase: "You cannot keep the peace where there is no peace to keep."
But cutting the KLA's supply lines in the midst of this war would make NATO troops participants in the conflict - and thus targets.
A second military option - threatening to bomb not just the Yugoslavs but the KLA if it breaks the ceasefire - would run into a different problem. The KLA has none of the air bases, tank parks and radar sites of the Yugoslavs. The guerrillas simply have no "hard targets" to bomb.
So far, military commanders have balked at the military options but the West has already begun trying to weaken the guerrillas politically.
Some KLA bank accounts in Switzerland and Germany have been frozen, damaging a new and still delicate fund-raising operation. Italian naval patrols operating off the Albanian coast to stop illegal immigrants crossing the Adriatic are also hunting for arms shipments which are bought in arms bazaars around the world, then shipped to Albania and on to Kosovo.
But the KLA is fighting back. Money is being transferred to the US, where many ethnic Albanians have been given citizenship - in Europe they must remain as guest workers. Citizens' money is harder to control than that of immigrants.
Meanwhile, the US is trying an alternative method, using carrots rather than sticks to influence the KLA. Last October, US envoys travelled to the KLA high command, based in Geneva, to present a "shopping list" of requests.
There were three: to have no links between the mostly-Muslim KLA and Islamic extremists, the so-called Mujahideen; to agree not to spread Kosovo's war outside its borders (no bombs in Belgrade); and to agree not to spread the war into the ethnic Albanian community in neighbouring Macedonia.
"We had already agreed to these points," says KLA spokesman Mr Pleurat Sejodiu. "Of course we agreed."
He will not say what the KLA was given in return - although in May the US took the unusual step of removing the organisation from its list of groups described as "terrorist".
Bringing the KLA "on side" might moderate its members' behaviour. The West still hopes they will drop independence demands in favour of autonomy for the province within Yugoslavia.