WASHINGTON — For people old enough to remember Vietnam, the transformation of the U.S. military has been momentous, one of the largest changes to ever affect a major American institution.

One can question the long-term impact of a powerful, costly military on a republic's character and budget. Since the Declaration of Independence, civilians have been given strong say in national defense to forestall the military governments that often have wreaked havoc on the world.

But few can argue that the modern U.S. military has transformed itself ahead of most institutions in the application of management strategies, social progress, technology, morale and ultimately, results. While institutions like the Catholic Church or big business have undergone crises over the past two years, the military has remained one of the most respected American institutions.

It was not that long ago that Vietnam veterans were spat upon when they returned home, when movies like "The Deer Hunter" explored the tortured psyches of a generation of young veterans. Only 23 years ago, U.S. soldiers failed to rescue Iranian hostages, leaving shattered helicopter hulls in the desert as metaphors for Jimmy Carter's days of malaise.

The turnaround began with a huge price, in the shadows of Vietnam. Ronald Reagan's military buildup of the 1980s helped drive federal budget deficits to record levels but also helped bankrupt Cold War foes and produced the early outlines of the "smart bomb" military that helped win Operation Desert Storm in 1991. The military, one of the first institutions to segregate races, has been a model of progress in recruiting and promoting minorities.

Iraq may have been the final piece of the transformation. Afghanistan, with the failures to destroy cornered terrorists at Tora Bora, had cast some doubts upon U.S. strategy. Despite second guessing early in the Iraq war, a quarter-million U.S. men and women and a strong British force routed a not-insignificant army in less than a month, with fewer coalition soldiers killed so far than those died in the Persian Gulf War 12 years ago. More young Americans died in the beginning hours of D-Day than died in both wars against Iraq.

And despite the deaths of innocents, the collateral carnage was not on the scale of previous wars, when Dresden-like hell descended upon cities and thousands of civilians died in a single night.

The swagger that Army Gen. Tommy Franks, the architect of the winning strategy, showed while convening a meeting in one of Saddam Hussein's golden-gilded palaces was in stark relief to the discredited military of Vietnam.

Religious references to war speak of a terrible swift sword. This is the U.S. military in 2003. And the generation of young Americans from which it is drawn is, unlike its baby boomer parents, among the most pro-military of any in American history.

A new book, "The Generation of Trust," by Harvard public policy professor David King and Harvard-educated economist Zachary Karabell, traces the transformation of the military to the infamous Tet offensive during Vietnam 35 years ago.

King and Karabell cite three broad strategies by the Pentagon to rebuild trust in the military:

— Improving battlefield performance.

— Making the military more professional.

— Constructing what King and Karabell called "a sustained Hollywood-focused campaign of persuasion, which was mainly gauged to attract a long line of new recruits."

The latter goal, the authors claim, was successful because the military played to generational differences in attitudes toward the military.

"Baby boomers, with the effects of Vietnam lingering, remain largely skeptical of the military," King and Karabell write. "Yet the children of the baby boomers, with the effects of the first gulf war coloring their view, are stronger supporters of the military than even their own Depression-era and World War II-era grandparents ever were."

There are many enduring images from this war. The Iraqi boy, Ali, with both arms blown off in a bombing raid that killed his family. The long lines of U.S. armor cruising across the desert. The statue of Saddam Hussein falling in a Baghdad square. Looting. Iraqis kissing American soldiers.

But as the nation-building phase begins, another dominant image will be of the cool professionalism of individual U.S. soldiers. It may have been the biggest byproduct of the Pentagon's decision to embed journalists with fighting units.