RIYADH, SAUDI ARABIA, FEB. 10 -- A hot and sweaty Gen. H. Norman Schwarzkopf had just finished a workout last August and was peeling off his clothes to shower when the hotline in his Tampa, Fla., bedroom rang. It was Gen. Colin Powell, chairman of the Joint Chiefs of Staff, calling to report that Iraq had just invaded Kuwait.

"Well, they've crossed," Schwarzkopf remembers Powell telling him. "And I said, 'I'm not surprised, you know. Now it's going to be interesting to see what they do.' "

The chief of the U.S. Central Command recalled that even then, he did not expect Iraqi forces to occupy all of Kuwait. "I thought they might go in, maybe beat up on the southern oil field, and then go back into Iraq."

In the six months since that telephone call, Schwarzkopf has stepped from a little-publicized military command onto the world stage as director of what may turn out to be the most intensive battle campaign since World War II.

Before television cameras, Schwarzkopf, 56, projects the image of a gruff but charismatic warrior who cares passionately about his troops. But in several interviews in the past six months, he emerged as a far more complex and introspective leader than his Stormin' Norman reputation might suggest.

In the corridors of the military operations center here, associates describe the tall, burly, 240-pound Schwarzkopf as a talented strategist and rigid perfectionist. He is characterized alternately as hot-tempered and intolerant, or charming and self-deprecating. Longtime acquaintances say his personality is a complex montage of all of those traits, and he calls any one to the surface at will, depending upon his audience.

"If you asked me to describe Norman Schwarzkopf in one word, I'd say 'tyrant,' " said an officer under his command in Saudi Arabia.

He has gained a reputation among many officers here for his scrupulous attention to news clippings and his penchant for chewing out subordinate commanders who give reporters quotes he feels are inappropriate. People who work for him say he is a difficult, demanding boss.

"My job isn't to go around and say everything is wonderful, everything is marvelous," Schwarzkopf said in response to such criticism. "That's not what I'm here for. That's not what my country expects, the families of all those soldiers expect of me, and it certainly isn't what the soldiers themselves expect of me."

"Probably the one expression everyone who has worked for me knows is, 'A good leader never walks by a mistake,' " he continued. "It's easy to turn your back on something. If I saw a situation that could potentially cost lives and I didn't do something about it and it did cost lives, I couldn't forgive myself."

Some senior military leaders in the Pentagon who have worked with Schwarzkopf in the past say they initially were concerned that his temper and demanding nature would impede his effectiveness in a delicate political situation where patience and diplomacy were critical, especially in the early days of forging a tenuous coalition among unpredictable Arab and Western states.

"We have all been pleasantly surprised," said one of those doubting associates, who served with Schwarzkopf during one of his five tours in the Pentagon. "He has handled the political sensitivities with great finesse."

Schwarzkopf, whose most idolized war hero as a cadet at West Point was Alexander the Great, seems to have slipped almost effortlessly into his newly acquired role as a molder of world events. But he has shaped this war on a foundation of lessons hard-learned from two combat tours in Vietnam, and from its bitter aftermath -- which left an indelible mark on his view of war and politics.

He first volunteered for duty in Vietnam and served as an adviser to a Vietnamese airborne division. Later he returned to become an infantry battalion commander. Lessons of Vietnam

"The toughest thing for me to handle was the reaction of the American public to the U.S. military as a result of the Vietnam war," said Schwarzkopf, who won two Purple Hearts in combat there and whose father was an Army general. "I had to really reevaluate the fundamental reason why I had chosen a military career to begin with and come to a decision whether I was still dedicated enough to continue, given the sort of stuff that was going on at that time."

That period has had a dramatic impact on the way Schwarzkopf and his senior commanders are running their current war, from the constant attention to the morale of troops to the way the war is portrayed to the American people.

"I can still remember {Gen. William C.} Westmoreland saying, 'The light is at the end of the tunnel, just give me a hundred thousand more,' and then he got a hundred thousand more and he said, 'The light is at the end of the tunnel, all I need is a hundred thousand more,' " Schwarzkopf said. "People can say anything they want about Central Command's plan" -- his fist slammed into the table -- "but the one thing they can't say is we came in here shyly."

Most associates would say Schwarzkopf has done nothing shyly in his career. From his earliest days as a lieutenant, he coveted the stars of a general and his own command of a division. In 1983, he was named commanding general of the 24th Infantry Division based at Fort Stewart, Ga. That division was among the first to deploy to Saudi Arabia last fall.

Schwarzkopf concedes that he is so competitive that "my family won't even play with me in Trivial Pursuit anymore." His father was a one-star, brigadier general who introduced his son to the Middle East when he was posted in Tehran. The younger Schwarzkopf said he was always determined to earn two stars, and "after that, everything else was gravy." War-Gaming in Tampa

When he took over as chief of the U.S. Central Command in 1988, he unsuccessfully fought Pentagon efforts to reduce the American military presence in his region of the world, where the eight-year Iran-Iraq war had just ended and the U.S. Navy was disbanding its escort missions for reflagged Kuwaiti tankers in the Persian Gulf.

"Oh, they were saying he had all those forces during the {Iran-Iraq} war, and now he's losing them all and he's fighting," said Schwarzkopf, who called those complaints against him "unfair." He said he logged 300,000 miles traveling from his Florida headquarters to the Middle East even before the invasion of Kuwait, and said he was attempting to convince his superiors of the need for continued strong ties to the nations of the Middle East.

During last year's annual staff war-gaming, Schwarzkopf developed a scenario in which Iraq was preparing to attack Kuwait. Even before the paper-and-computer exercise ended last August, the hotline in his bedroom rang with the call from Powell.

Schwarzkopf said he drew heavily on his command's war-gaming when he flew to Washington the next morning to brief President Bush and the National Security Council on military options.

In the buildup of the initial wave of 240,000 troops, he said, there were few deviations from the war-game plan. One exception, however, was the Patriot missile.

"During the war game, {Army Lt. Gen.} John Yeosock," who now heads all U.S. Army forces in the gulf, "deliberately enticed me down to his headquarters, where he captured me and made me sit through a long briefing on Patriot to tell me how important Patriot was to him, and it made sense what he said," Schwarzkopf said. "So when we decided to flow the forces here, based upon the briefing that he had given me, I decided to raise their priority and get more of them in-country."

Outside of the war room, a far different Schwarzkopf emerges -- projecting the image of a four-star general who can relate to the emotional sufferings of a buck private pining for his family as he sits in the dust of the Saudi desert.

"My attitude coming over here this time was different," Schwarzkopf mused in an interview with The Washington Post last fall, a few weeks after he moved most of the U.S. Central Command from its Tampa base half a world away to Riyadh. "Inside me there was this sort of resentment -- not against anyone, but something I didn't feel two times in Vietnam."

"The first time in Vietnam I volunteered," he said. "The second time it was just me and my wife, and she understood. But this time it was me, my wife, three kids and my dog, and we all had plans as to what we were going to be doing in September. And none of them called for Dad to be away from home in the middle of the Saudi Arabian desert.

"Saddam Hussein not only disrupted my plans, but my whole family was affected by this," he said, pausing. "But Schwarzkopf, you're not alone, every other soldier feels the same thing."

In the same wistful tones used by many of those soldiers, he counts the time in Saudi Arabia by the events he has missed. The day he left Tampa for the Middle East, he was supposed to be attending parents' orientation on daughter Jessica's first day at the University of Tampa. "She was heartbroken -- I was heartbroken."

He gave daughter Cynthia a new fishing rod for her 20th birthday, but wasn't home to help her break it in. He missed his cherished dove and turkey hunting trips with his friends in Tampa. It has been a long six months for a man who planned to retire this summer and look for a job that would pay the college tuitions of two daughters and the private school expenses of his son Christian, 13. 'Muddy Boot Soldiers'

Instead, Schwarzkopf, who also left a pet gerbil and python at home in Florida, has found himself at the climactic point in a 32-year career that began as an enthusiastic young cadet at the U.S. Military Academy, where he and his colleagues debated the virtues of their favorite war heroes.

"I had tremendous admiration for Alexander the Great because Alexander the Great was a young leader," Schwarzkopf said. "He did everything his troops could do and did it better. He conquered all of the known world by the time he was 30."

Now, as he prepares to follow generations of wartime commanders into the history books, Schwarzkopf said his view of the military role model he hopes to emulate has matured since his early fascination with Alexander the Great. Now it is Civil War generals such as Ulysses S. Grant and William T. Sherman and the fabled World War II tank commander Creighton Abrams, who succeeded Westmoreland in Vietnam, that he admires.

"They were all muddy-boot soldiers," Schwarzkopf said. "I think all of them probably intensely hated war. And yet, at the same time when they had to, they waged war furiously -- and they didn't enjoy doing it."

There is another side to those generals that Schwarzkopf believes he can identify with.

"They never, I don't think, considered themselves particularly dashing and handsome and romantic in their uniforms," he said. "And perhaps it's my physical characteristics that make me realize that even on my best day, I could not ever be considered dashing."