The Russian military continues to stick a collective thumb into NATO's eye at every opportunity in the wake of the Kosovo war. This is no passing fit of pique in Moscow. At some level, Russian national interest as well as Russian national pride has been injured.

The military lessons of NATO's devastating 78-day air campaign against Serbia are being drawn by general staffs around the globe. Nowhere will the meaning of Kosovo be studied more intently, or grimly, than in the Kremlin. Russian-supplied weapons and defensive strategy were defeated by NATO as thoroughly as were Slobodan Milosevic's political goals.

The end of the Cold War does not prevent senior military professionals in Washington and Moscow from continuing to grade themselves, their weapons and doctrines against each other. Kosovo must be judged a military disaster for the inheritors of a Soviet model that relied heavily on ground radar-controlled air defense, and a jump forward for U.S. offensive technology.

This sense of strategic failure may be even more important than the often cited but somewhat tenuous factors of Slav cultural or political solidarity in explaining the Russian military's obstructive behavior in dealing with the West over Kosovo.

The Russian dash to the Pristina airport, the constant challenging of the terms of the deployment deal its political leaders accepted at Helsinki and even the recent buzzing of Iceland with strategic bombers all fit the pattern of a military establishment intent on showing anger and unhappiness and clawing back some self-respect, whatever the diplomatic costs.

The Soviet Union pumped billions into its ground-controlled air defenses in the 1980s and persuaded its friends and clients to take that approach, while the United States and its allies funneled resources into offensive air technology and air-based interceptor defense.

Kosovo rewarded the U.S. effort. Milosevic's highly rated air defense system, which contained modern Western-manufactured equipment as well as Soviet-era surface-to-air missile batteries, proved wholly ineffective against U.S. stealth warplanes that delivered a new all-weather guided bomb onto critical strategic targets.

The combination of B-2 bombers and Joint Direct Attack Munition (JDAM) satellite-guided bombs were for some U.S. senior military officials the most important technical innovation of the Kosovo campaign.

JDAMs, which entered the U.S. Air Force inventory only a few weeks before the Kosovo air war began, do about the same damage with the same accuracy as the laser-guided bombs that achieved fame in Operation Desert Storm against Iraq. But they only cost about $20,000 each -- one-third the price of a laser-guided bomb and a fraction of the $1 million an air-launched cruise missile would cost. War planners appreciate them most of all because they do not require clear weather, an important factor in a theater like the Balkans.

Operating with a limited supply, the Air Force is said to have dropped between 300 and 400 JDAMs out of a total 23,000 bombs and missiles used in the campaign against Serbia.

Equally telling was the fact that less advanced NATO aircraft were also able to overwhelm the Serb defenders, who seemed to have calculated that they faced certain destruction if they switched on their radars to track the attackers. Without electronic guidance, the anti-aircraft missiles the Serbs fired into the skies were useless.

Russian-American direct military contacts have ceased since the end of 1998, as U.S. forces prepared for the air attacks they subsequently carried out on Baghdad and Belgrade without significant opposition or losses. Despite the surface harmony Bill Clinton and Boris Yeltsin periodically proclaim, hopes of mutual military cooperation that flourished at the end of the Cold War are now on life support, and deteriorating rapidly.

They are deteriorating not only because of underlying conflicts over Kosovo but also because of the new demonstration of U.S. technological superiority. The fears and uncertainties now present in Moscow's military are too deep to be overcome with presidential rhetoric and bearhugs between Boris and Bill. A deep reassessment of Russian-American relations is needed in both capitals.

That is not the only cloud present in the silver lining of Milosevic's capitulation to U.S. pilots, who did not suffer a single casualty to hostile fire. American generals must now worry that their experience in Kosovo has made war look too easy, at least for technologically superior attackers.

They must guard against the temptation political leaders will no doubt feel to use professional forces, and the latest wonder weapons, as instruments of diplomatic frustration. War -- even humanitarian war -- must always be a last resort.