As NATO launched its first attack on a sovereign country in its 50-year history, analysts warned that the U.S. may have committed a mistake in risking long-term strategic goals by snubbing Russia's opposition to the bombing.

Russian politicians of all stripes angrily condemned NATO's actions, many saying that bombing Yugoslavia was tantamount to an attack on Russia. The fierce rhetoric leaves no doubt that relations between Russia and the U.S. have plummeted to their lowest point in almost two decades.

On Thursday, as American and allied warships and bombers continued to bomb targets in Yugoslavia for a second night, U.S. President Bill Clinton warned that the organisation would continue its raids until Belgrade agreed to sign a peace settlement with Kosovo's ethnic Albanian majority.

Yugoslavia meanwhile declared it would break off diplomatic relations with the U.S., Britain, France and Germany.

Witnesses in Yugoslavia said they saw bomb explosions on the outskirts of Belgrade, Kosovo's capital Pristina, Novi Sad in northern Yugoslavia, and an airport in republic of Montenegro, Reuters reported.

The Yugoslav military reported attacks in seven Yugoslav towns.

According to officials in Washington, U.S. forces launched Tomohawk missiles from ships in the Mediterranean and Adriatic seas and cruise missiles from B-52 bombers based in Britain.

British Prime Minster Tony Blair said that Harrier bombers based in Italy and a British submarine had contributed to the attack, AP reported.

Clinton said American diplomatic efforts had reached a dead end and Serb troops were terrorising and murdering civilians in Kosovo province of Serbia, Yugoslavia's dominant republic.

"Only firmness now can prevent greater catastrophe later," Clinton said in Washington on Wednesday.

Clinton said the U.S.'s three main objectives in the bombing were to demostrate NATO's seriousness in supporting peace, deterring Yugoslav President Slobodan Milosevic from carrying out further attacks on civilians, and reducing Serbia's military capability, Reuters reported.

But U.S. efforts to contain the leaking of sensitive military technologies and weapons of mass destruction, along with the desire for long-term political stability in Moscow have been put at risk, reports say.

The U.S. is seen on the world diplomatic stage as having treated Russia as if it could do nothing to stop an attack on Yugoslavia.

Indeed, Russia has so far only issued threats of punitive measures, including those by the ministries of defence and foreign affairs.

Those threats came following Prime Minister Evgenii Primakov's decision to cancel a trip to the U.S. while en route to Washington after he had been informed that NATO would go ahead with its attack.

Under proposals which have yet to be put to President Boris Yeltsin, Moscow could review its cooperation with Iran, send weapons to Belgrade and replace nuclear arms in Belarus, ITAR-TASS reported.

Russia also sees the possibility of abandoning its accords with the United States on deliveries of arms and military materiel to Iran.

But the real threat to both Russia and the West is the looming fact that Russia may soon default on its international debt and blame the United States for an economic collapse.

Russia must repay 17.5 billion dollars of interest on its foreign debt this year. The first debt repayments are due in May, and analysts fear there is a large probability of another default for Russia.

Observers say that would seriously damage a volatile Russian domestic situation. And what western countries fear most is destabilisation in a country containing thousands of nuclear weapons.

The United States has, since the collapse of the Soviet Union in 1991, steadily voiced concern about Russia's control over materials used in the manufacture of nuclear, chemical and biological weapons.

The US-Russia Joint Commission, a bilateral structure headed currently by Primakov and Vice President Al Gore, has concentrated on boosting control of nuclear weapons. Meanwhile, the U.S. has plowed hundreds of millions of dollars into various military conversion and stabilisation programmes.

But despite its reliance on cooperative relations with Moscow to achieve these and other objectives, the United States has opted at present to ignore Russia's alliance with Serbia and its bitter opposition to military attacks on its "brother" Slavs.

Most analysts say the U.S. feels it can afford to compromise some of its long-term goals by bombing Yugoslavia because Russia is truly no condition to undertake any action to oppose the move.

But one immediate large victim of the NATO bombing will most likely be the 1993 START II treaty, which would reduce the number of U.S. and Russian long-range nuclear weapons. Russia's Duma lower house of parliament has yet to ratify the treaty.

U.S. officials have said their cooperation with Russia will remain unchanged, but Primakov said that the faultline between Moscow and Washignton would become permament if strikes against Kosovo continued.