This summer, we observe the 50th anniversary of the start of the Korean War. As we look back at the armed forces of 1950, it is startling to see how much airpower has evolved since then--and how much the land power and sea power of today resemble themselves a half century ago.

The US position as the world's preeminent military power is attributable mainly to its superiority in air and space. Our land forces are better than the armies of other nations, but that is not the big difference between our capability and theirs. From the Persian Gulf War in 1991 to the Kosovo campaign in 1999, aerospace power has been the dominant element in armed conflict.

That ought to bear heavily on the next Quadrennial Defense Review, which is already under way. However, neither the first QDR in 1997 nor any of the other alphabet soup defense reviews of the 1990s gave more than nominal recognition to the dominance of aerospace power. The last QDR, in fact, cut the Air Force deeper than it did the other services.

The forthcoming QDR report is not due to Congress until September 2001, but the Joint Staff and the services began work on it several months ago. The watchword this time around will be the "transformation" of the armed forces from their Cold War configurations to serve the changing needs of a new century.

That would seemingly stand the Air Force in good stead. In April, the Congressionally chartered Hart-Rudman Commission on National Security said that US armed forces of the future "must be characterized by stealth, speed, range, accuracy, lethality, agility, sustainability, reliability-and be supported by superior intelligence." The list fits the Air Force like a glove.

But how much will transformation really count when the review gets rolling? There is a strong chance this QDR will deteriorate-as the last one did-to a budget exercise and an interservice scramble for shares of the funding.

Almost immediately, transformation runs into a financial brick wall. The services have been told to "transform within their means." In other words, they should not expect any additional money.

At their present budget levels, the services cannot meet the assigned yardstick of fighting two regional conflicts more or less simultaneously. They are stretched and stressed by expanded peacetime operations. They have fallen behind in force modernization They are constantly on the scout for more funding.

By calling on the services to transform themselves, the QDR creates more pressure--and provides an opportunity--for them to seek a transfusion from somebody else's budget. At least one service has made just such a move.

The problems are not entirely fiscal, though. There is less enthusiasm in the Pentagon for transformation than you might believe from listening to statements made for public consumption.

About 10 years ago, planners behind the scenes began talking about a "Revolution in Military Affairs." The attrition model of warfare, with the bloody clash of force on force, is no longer inevitable. Change is possible by a combination of stealth, long range precision strike, and information technologies.

This is not to say technology can do it all by itself, but rather that the burden in warfare has shifted. In many instances, we may be able to achieve our strategic objectives, or come closer to achieving them, without piling up large numbers of casualties on the ground.

As "Joint Vision 2010" put it four years ago, "We will be increasingly able to accomplish the effects of mass--the necessary concentration of combat power at the decisive time and place--with less need to mass forces physically than in the past."

Such thoughts do not set well with those who have a vested interest in the massing of forces. In recent years, therefore, we have seen a continuing attack on technology and airpower. The theme, pushed in the internal and trade press and sometimes picked up by the popular media, is that technology is undependable, airpower is overrated, and that it is somehow cowardly to avoid casualties.

We are supposed to believe, for example, that the decisive element in the Gulf War was the 100-hour ground action and that NATO was successful in Operation Allied Force last year because of the implied threat of ground power--which was not engaged--instead of the 78-day air campaign.

The test of the 2001 QDR will be how it deals with these ungainly issues, and the financial questions may be easier than the conceptual ones.

In 1997, there was little resistance to the QDR stipulation that the defense budget would not increase. Although the services and the Joint Staff had done the workup, the Office of the Secretary of Defense had final say, and the QDR was a policy document of an Administration that was proposing reductions to the defense budget every year.

The next QDR report will be signed out by a new Administration, and this time the services may take a stronger position on fiscal guidance they know to be unworkable and unwise.

The other barrier is the more difficult one.

After everyone gives transformation their best shot, the distinctive military advantage of the United States is still going to lie with its aerospace forces. And that will be hard--perhaps impossible--for some of the key players in the QDR to swallow.