Tension Simmers

Launched on March 24, 1999 -- after the collapse of peace talks between then Yugoslav President Slobodan Milosevic and Kosovo Albanian separatists -- the bombing campaign drove Serbian troops out of Kosovo, set the foundation the deployment of NATO peacekeepers and a UN civilian mission to run the then Serbian province.

NATO plans no special occasions to mark the 10th anniversary of the war on Yugoslavia, which meanwhile disintegrated further when Montenegro split from Serbia in 2006.

Serbia will commemorate the anniversary on Tuesday by sounding the air-raid sirens used to signal the end of bombing sorties.

Serbia's Prime Minister Mirko Cvetkovic called the NATO bombing campaign illegal and "contrary to international law."

"The air strikes have not solved problems in Kosovo, and did not help to bring peace and the rule of law," Cvetkovic said at a special meeting of the cabinet to commemorate the attacks. "On the contrary, they resulted in ethnic cleansing and gross violations of human rights, international standards and fresh tensions."

The alliance's action, which was not sanctioned by the United Nations Security Council, undermined Milosevic's power and is largely thought to have played a major role in his being sent to The Hague to stand trial for war crimes. He died in 2006 before the court could issue a verdict in his case.

A necessary war

Western leaders saw NATO's air war, dubbed Operation Allied Force, as the only way to end the 1998-1999 violent crackdown by Milosevic's forces on the Kosovo Liberation Army and its supporters.

"I look back on that extraordinary last meeting with Milosevic, with a feeling that what we did was necessary and the right thing to do," Richard Holbrooke, who served as the United States special envoy to the Balkans, told reporters on Saturday.

"The people of Kosovo are better off than they were as part of Serbia, and Serbia is better off facing the future rather than working back to a mythic past," he added.

Then US President Bill Clinton also said at the time that the West had a "moral imperative" to take action against Milosevic.

The North Atlantic Treaty Organization, in what was its largest military operation, set out to destroy dozens of targets. In its 78 days of bombing, however, it also hit public infrastructure like bridges and railway tracks as well as homes, refugee convoys, a hospital and the Chinese embassy in Belgrade.

Human Rights Watch has estimated that about 500 civilians lost their lives during the bombing campaign, five times less than the Yugoslav government claimed at the time.

Diverging views of war in Kosovo

For ethnic Albanians in Kosovo, where they accounted for 90 percent of the region's population despite being a minority in Serbia overall, the war put a welcome end to their suffering at the hands of the Serbian majority.

"The appearance of combat airplanes in the sky above Kosovo was a message of salvation for the people here," Kosovo Justice Minister Nekibe Kelmendi told AFP.

But for the Serb minority, the campaign marked the beginning of their agony.

"It was revenge for Serbian disobedience," said Radoslav Radovic, a 57-year-old from the Serb-run half of Kosovska Mitrovica, a northern town that still simmers with ethnic tensions.

Radovic told AFP he believes the West declared Serbia guilty for "defending its integrity and its territory."

Fearing ethnic Albanian reprisals, tens of thousands of Kosovo Serbs fled their homes for Serbia proper, with only a handful returning in the past decade. Of the 120,000 ethnic Serbs estimated in Kosovo, most live in the northern region that borders Serbia or in small enclaves in southern areas.

Tensions run high after independence

Tensions have remained high, especially since Kosovo's parliament unilaterally seceded from Serbia in February 2008, a move that has been recognized by 56 nations including the United States and most of the European Union.

Officially, the United Nations remains in charge of Kosovo. The 15-nation Security Council has not been able to alter the UN mandate because its members are split over what to do with the UN presence there and the legality of Pristina's declaration of independence.

Russia, a permanent veto-wielding member of the Security Council and Serbia's ally, has said it would not recognize an independent Kosovo and has supported Belgrade's bid to challenge the declaration before the International Court of Justice in The Hague.

Under a plan agreed to last year, police, customs officers and judges in the Serb-run areas of Kosovo remain under the UN umbrella, known as UNMIK, while their Albanian counterparts work with a European Union police and justice mission called EULEX.

Many Kosovo Albanians have come to view the UN presence as an obstacle to independence, UN Secretary-General Ban Ki-moon said in a report published Thursday.

"There is a perception among many Kosovo Albanians that the mission's tasks have been accomplished and its continued presence is an unwelcome obstacle to the desire for Kosovo to function as a sovereign state," Ban said in his latest report to the Security Council on UN activities in Kosovo.

Ban's report did not make recommendations on how to move forward as uncertainty in the region appears likely to continue.