WEST POINT, N.Y. -- For weeks, America's oldest garrison, its Gothic training ground for war and national symbol of martial achievement and valor, has been enveloped in troubled tranquility.

By first light each day, 4,400 cadets are awake, pulling on dress grays or camouflage gear and spit-shined combat boots for an icy march to the cavernous mess hall.

Classes in military tactics, geography, physics and poetry proceed as they have since 1802, but the United States Military Academy is a school for war. As the nation prepares for what may be its first major armed conflict in nearly 20 years, residents of this serene and snowy fortress have turned their minds to a duty they have rarely envisioned.

With nearly 250,000 Army colleagues in the Persian Gulf, reality has descended abruptly on this granite enclave high above the frozen Hudson River. The 998 graduating seniors -- "Firsties" who have survived the wearying challenges of a West Point education -- yesterday selected the branch of service they wish to enter. Only a year ago, with the Berlin Wall crumbling and careers as officers looking grim, positions in armored units with tanks had become the least favored.

But as one officer here said Monday of Iraqi President Saddam Hussein, only half in jest, "He may have singlehandedly saved the armored division." Armor appears to be the most popular specialty among the Firsties, and Army officials said it is difficult to envision a future force that would not have to respond to a desert threat.

"Does Iraq change our programs, our mission or our determination to prepare leaders?" asked Lt. Gen. Dave R. Palmer, the academy superintendent. "Of course not. But it does provide a sharp reminder of what we are here to do. We cannot be a remote bastion. If our nation goes into battle, we are here to lead it."

Many students and some teachers here have never had to consider that fact seriously. Before Iraq invaded Kuwait, world events seemed to have transported the United States beyond this possibility. Even at West Point, people began to forget what Plato wrote, that only the dead have seen the end of war.

The dead are everywhere here in statue and relief, on plaques, monuments, scrolls and altars. The cemetery is almost full, with national heroes and those who did their duty without fame. Perhaps no institution has more visible history. Plebes still must recite on demand Gen. Douglas MacArthur's famous farewell speech to his alma mater in 1962.

"Duty, honor, country," he said in part. "Those three hallowed words dictate what you ought to be, what you can be and what you will be. They are your rallying points. . . . "

In the school library, where academy historians have assembled class rings dating to 1835, the ring of 2nd Lt. Courtney L. Barrett Jr., class of 1950, killed in Korea, evokes gasps. The stone has been blown away, leaving a jagged hole and the golden class insignia blunted beyond recognition.

"When you see something like that, how can it not scare the hell out of you?" said Omar Jones, a cadet from Ellicott City, Md. "We are human. Our friends are all over there. We are trained to be prepared to fight and to lead. We are not trained to seek war or to love war. Only people who know nothing about it could do that."

Theoretical adventures of the classroom have ceased to be imaginary. There is new purpose to map courses and lectures. Rumors, denied by West Point officials, have swept the campus that, for the first time since World War II, a senior class may be graduated early.

"We all got serious about our lives when we came here," said John McDonald, a cadet from Rochester, Minn. "Now we are even a little more serious than we thought we could be."

"It's not a game," said Capt. Charles Sniffen, who teaches military tactics. "It's their job. As soon as they understand that, the better soldiers they will be."

Unless a conflict lasts for at least a year, the cadets know that they are unlikely to see combat.

"It'll be over in a week, two at most," said Michael Best, a cadet from Florida.

"No way," one his classmates said. "It is going to last a lot longer than that.

"But I'll tell you one thing," he continued, very matter of fact. "We are going to win it. And you want to know something else? We'll win the next one too."