Washington is a city of careers: Job changes both cause and reflect seismic political events. Such a shift is now underway at the Pentagon, where Gen. Wesley K. Clark, the NATO commander who recently got Slobodan Milosevic to say uncle in Kosovo, was told on Tuesday to look for a new job.

Ingratitude, or history on the march? Some of both may be involved. Clark, not given to underestimating his place in history, can take solace in reflecting on the fates of Winston Churchill at the end of World War II or George Bush after Desert Storm. Their victories were also rewarded with eviction notices from electorates ready to move on to new subjects.

The Pentagon has presented a slight curtailment of Clark's three-year tour as a routine act of bureaucracy. Clark has made it clear in his public statements since the change was leaked that the move came as a surprise and an affront.

Clark was due to serve as the commander of U.S. forces in Europe and the top general at NATO until next July, but he will now leave in April. Seven of 10 of his predecessors served more than three years in the military's most political job, The Post's Pentagon correspondent, Bradley Graham, notes.

The change at NATO occurs as Europe moves from the immediate problems of waging war in the Balkans -- a task for which Clark was ideally suited -- to the broader mission of managing a major overhaul in European and U.S. responsibilities within the alliance.

Defense Secretary William S. Cohen is clearly living under auspicious signs: Clark's reported successor as NATO commander, Air Force Gen. Joseph W. Ralston, is the perfect candidate to cope with the political pitfalls presented by the vast and growing disparity between U.S. and European defense capabilities.

Ralston, who has served as the Pentagon's chief trouble-shooter in his post as vice chairman of the Joint Chiefs of Staff, has impressed congressional committee chairmen and the White House with his conceptual abilities and political feel as well as his military skills. He will need all of that in the NATO job over the next three years.

The Kosovo campaign underlined the relative military weakness of NATO's European members, even as they were pledging to take on more responsibility for defense within the alliance. European planes could not take on complicated missions that had to be carried out by U.S. aircraft.

The war's outcome catches Europe in a double bind: It shows the continent will have to increase military spending to meet its declared ambitions, but it simultaneously makes that more difficult by saddling Europe with heavy reconstruction costs in the Balkans.

France already devotes 54 percent of its gross domestic product to government spending; for Germany and Europe in general the figure is 47 percent, compared with 31 percent for the United States. Finding the extra resources for expanding defense capabilities and rebuilding the Balkans will be hard if not impossible for most governments.

The conduct of the campaign, carried out almost entirely by the U.S. Air Force, also raises serious questions about Europe's political will to fight modern, highly destructive wars.

Clark has now publicly confirmed in interviews that his demands to hit Milosevic harder earlier -- to "go downtown" on the first night of the war with strategic bombing -- were blocked by political concerns imposed by governments in Europe and to some extent by Washington.

These political restraints served to prolong the war and the agony of the Kosovars.

Fortunately for them and for NATO, discretion was never the better part of Clark's valor. A prickly, pushy commander of considerable intellect and abilities, Clark was a burr under the saddle for the Pentagon, the White House and Washington's European allies throughout the war.

He prodded them relentlessly, both privately and with veiled public statements that drew attention to the campaign's shortcomings. He eventually got the politicians to intensify an air war that was beginning to risk failure, as Clark and his subordinates outline in detail and with candor in an article by Michael Ignatieff in the Aug. 2 edition of the New Yorker magazine.

Ignatieff quotes Clark acknowledging his frustration with "the only air campaign in history in which lovers strolled down riverbanks in the gathering twilight . . . to watch the fireworks" -- until May 24, when heavy munitions destroyed the transformer yards of the Yugoslav power grid and changed the course of the war.

Clark, a member of the U.S. negotiating team at Dayton that produced the Bosnian peace accord, brought personal involvement and experience in the Balkans with him to the NATO job. He also brought along a willingness to stand up for his beliefs.

That quality helped end a war and save lives. It may also have cost Clark a few months of his tour in one of the world's most important jobs. If so, it was a trade worth making.