WASHINGTON — Leaders of the North Atlantic Treaty Organization, wrapping up their 50th anniversary summit here, pledged Sunday to use all necessary force to defend the embattled countries on Yugoslavia's borders if the Kosovo war infects the rest of the Balkans.
The presidents and prime ministers of the 19-nation alliance extended what NATO officials described as the next best thing to a temporary NATO membership card to the seven "front-line" states, promising that an attack on any of them would draw an immediate and overwhelming response.
NATO spokesman Jamie Shea said the assurances were not the same as NATO's all-for-one, one-for-all alliance defense policy, "but they are very strong indeed, much stronger than we have ever done before in making clear that an attack on any of these countries would require a response."
Leaders of the seven neighboring countries--Albania, Macedonia, Bulgaria, Romania, Croatia, Slovenia and Bosnia-Herzegovina--met Sunday with the NATO chiefs. Two other nations in the Balkan region, Greece and Hungary, are full members of the alliance.
According to several officials who attended the session, all seven countries expressed support for NATO's bombing campaign against Yugoslavia. They urged the alliance to do whatever is necessary to stop Yugoslav President Slobodan Milosevic's "ethnic cleansing" in Kosovo, a rebellious province of Serbia, Yugoslavia's dominant republic.
Several of the seven are providing direct support to the NATO campaign, officials said. About 30,000 NATO troops are stationed in Albania and Macedonia, and several thousand other allied troops are in the peacekeeping force in Bosnia. Romania and Slovenia decided last week to allow NATO warplanes to use their airspace, and Bulgaria is expected to follow suit during the next few days.
"If Belgrade challenges its neighbors as a result of the presence of NATO, we will respond," President Clinton said.
In other developments Sunday, the 33rd day of Operation Allied Force:
* NATO's top commander, U.S. Army Gen. Wesley K. Clark visited 3,300 troops in Albania, praising the air campaign as effective and "on time." He said he was pleased with the NATO-led effort to ease the plight of refugees who have flooded into that country.
* Deputy Secretary of State Strobe Talbott left for Moscow for consultations about Russia's diplomatic offensive to end the conflict. U.S. officials said they will support the Russian effort as long as it focuses on persuading Milosevic to accept NATO's conditions for ending the bombing: an end to "ethnic cleansing" in Kosovo, withdrawal of Yugoslav forces from the province and the return of refugees under the protection of an international peacekeeping force.
* Despite unfavorable flying weather, NATO warplanes pounded Yugoslav targets, hitting the now-familiar mix of military infrastructure and troop concentrations. A NATO military spokesman said that the planes faced little resistance and that all returned safely to their bases.
* Leaders of the rebel Kosovo Liberation Army called on NATO to boost their dwindling supply of weapons and to immediately dispatch Apache helicopters to Kosovo to strike back against the Serbs. Speaking to reporters in Kukes, Albania, KLA representatives claimed sporadic successes in recent firefights with Serbian soldiers but acknowledged that their troops are badly underequipped.
* Refugees fleeing Kosovo related some of the grimmest accounts to emerge from the province so far. In Macedonia, new arrivals told relief workers of Serbian paramilitary forces entering villages, ordering residents out of their homes and opening fire on them.
* A Greek humanitarian convoy arrived in Pristina, Kosovo's provincial capital. The six trucks each carried about 20 tons of food and medicine donated by the Greek government, according to an official with the Greek Embassy in Yugoslavia.
In their daily briefing, NATO military leaders said the Yugoslav army and the KLA continue to skirmish, especially in the rebel army's strongholds near the Albanian border. British Foreign Secretary Robin Cook noted that Milosevic claimed last month to have destroyed the KLA but that the rebel army has not only survived but increased its operations.
In Kukes, KLA leaders said the guerrillas killed six Serbs in one recent battle, 10 in another confrontation and three in a third attack, although they offered no firm reports on casualties among their own troops.
"The thing we are urgently asking for from the NATO alliance is to give us a modern arms supply," said a KLA military spokesman who was dressed in camouflage garb and identified himself only as Leopard 2. "At the same time, we are asking NATO to start using helicopters to strike Serb troops."
Another KLA representative, Gani Sylaj, argued that the rebels, if properly armed by NATO, would reduce casualties among alliance soldiers once NATO decides to send ground troops into Kosovo.