DON'T PANIC if you hear a one-megaton nuclear bomb is headed your way. Lt. Gen. Daniel O. Graham, U.S. Army (Ret.), has some advice for you. Walk briskly for about 59 minutes, the general says, 4.2 miles to be precise, then hide behind a lilac bush. Do that, and "you will not be hurt."

Graham relishes such advisories, which tend, he observes, to drive "the antinuke people" wild. How one would know where ground zero is so one could be sure to be walking away from it rather than toward it is not explained, but never mind. The blunt and raspy-voiced Graham likes to command attention, especially if it leaves the other side sputtering.

The former chief of the Defense Intelligence Agency, a Pgon version of the CIA, Graham has been doing a fair amount of that as director of High Frontier Inc., an organization dedicated to the proposition that America can be made "safe from attack by Soviet nuclear missiles."

Graham and High Frontiersmen foresee a network of space-based weapons to knock out incoming Soviet missiles. It would replace the longstanding doctrine of mutual assured destruction, which relies on the presumed certainty of an American nuclear counterattack to deter the Soviets from launching their missiles in the first place.

The project, in the form of President Reagan's Strategic Defense Initiative, sometimes known as Star Wars, is moving forward, less speedily than Graham would like, but still at a controversial, multi-billion-dollar clip. The Soviets, in turn, have cried foul, charging that an antimissile shield would simply tempt the United States to launch a crippling first strike without having to worry about effectiveretaliation. Graham, a West Pointer who began in the Quartermaster Corps, has been claiming much of the credit for the Star Wars initiative since President Reagan announced it in a speech in 1983.

"We (at High Frontier) are the people who caused the president to sound off a year ago in favor of a strategic defense initiative -- that is, defense in space," he told the Washington Times in a 1984 interview. "We went public in March 1982 and by March 1983 we had the president of the United States going our way."

Such modesty is typical for 60- year-old Danny Graham, who, when asked at a recent courtroom appearance how many stars he used to wear, shot back: "Six. Three on each shoulder."

Other SDI advocates, as well as critics, say Graham overstates his importance, but most agree he played a significant role in promoting the idea when he was a Reagan campaign adviser in 1980.

"His most important contribution was that he, in fact, put it on the public agenda," said Phil Truluck, executive vice president of the Heritage Foundation, a leading bastion of pro- SDI thought. "He got us interested in it. And we've had many meetings at Heritage on the subject."

A prominent SDI opponent, John Pike of the Federation of American Scientists, agrees: "High Frontier has probably done more to create some public constituency for this program than anyone else. A lot of discussion has focused on why the administration wanted to do this. High Frontier was instrumental in letting them think they could get away with it."

An early supporter of what he calls a "technological end run on the Soviets," Graham formed High Frontier as a nonprofit organization in September 1981 and around the same time, he says, he raised some $500,000 in private funds, "mostly from individuals."

Graham had been on the staff of the conservative American Security Council, headed by John Fisher, but Fisher, Graham said, "really didn't think much of this idea." Graham found a more receptive audience, not to mention "a tax-free pocket," at the Heritage Foundation. "So the checks were made out to Heritage, but they really had nothing -- little -- to do with it," Graham said.

By March 1982, Graham had put together a team of scientists, engineers and retired military officers to produce a 175-page study under the Heritage imprimatur proposing a "layered defense" in which nonnuclear weapons shot from satellites in space and from ground bases in this country would destroy incoming Soviet missiles.

Graham maintains it could all be put into place in about 10 years for about $40 billion, using largely off- the-shelf technology. In one mailing last year, he asserted that his "shotgun satellites," firing clouds of high- velocity pellets and deployable in five or six years, "alone would wipe out 80 percent of any mass ICBM attack while it is still over Soviet territory."

Critics have ben astounded. Not even the Pentagon's Strategic Defense Initiative Organization is contemplating such results. The administration has its eyes on longer range research and more exotic technologies.

HIGH FRONTIER appears to be flourishing. It occupies the entire 10th floor of a downtown Washington office building and has a full-time staff of 20, income of about $3 million a year, a smoothly written monthly newsletter with a circulation of 56,000, a network of more than 100 volunteer speakers and a string of subsidiary operations including a European affiliate based in Rotterdam, the High Frontier Europa Foundation.

Atop High Frontier itself is a four- member board of directors that includes Graham; his deputy, retired Air Force brigadier general Robert Richardson III; chief of staff Bob Billings; and Marianne Mele Hall, who quit as chairman of the Copyright Royalty Tribunal in May following a furor over her work on a book with racially disparaging passages. The main author of the book, Foundations of Sand, Lawrence Hafstad, and coauthor John Morse, a retired Navy captain, were also members of the team that produced the 1982 High Frontier study.

"Most of our money comes from fairly large donors," Graham said in an interview. "That's people (who give) from $500 up every few months. We have a few $100,000 types . . .Direct mail brings in about a fifth of what we get."

Other endeavors include a lobbying arm called Americans for High Frontier, which, a spokeswoman says, is "General Graham basically," and a political action committee called the American Space Frontier Committee, which was organized in the fall of 1983 with Graham as board chairman and Robert K. Dornan, who has since become a Republican representative from California, as president.

"Danny sent me around the country, making speeches for SDI," Dornan says. "The message was that this was lovable, because it's nonnuclear." Dornan acknowledged that the lovability argument has been tarnished because the administration's SDI funding plans include research into "promising concepts which would use nuclear energy to power devices" such as Dr. Edward Teller's proposed X-ray laser. But Dornan -- and Graham -- reason that "that kind of technology should be pursued," even if undesirable.

The PAC made barely a ripple in last year's congressional campaigns. It spent nearly $365,000 in the 1983-84 election cycle, but most of the money went for operating expenses, such as direct mail and fund-raising costs. It gave out only $36,199 in contributions to favored candidates, including Dornan, and spent another $1,732 trying to defeat other candidates, including Rep. George Brown (D-Calif.).

Brown, who was targeted along with Rep. Mel Levine (D-Calif.) for forming a congressionally based Coalition for the Peaceful Uses of Space, said as far as he could tell, High Frontier's "bark is worse than their bite."

There are, however, no toothless views about Danny Graham, as illustrated by his role in the CBS-Westmoreland libel trial last winter when he testified in connection with allegations that he had doctored estimates of enemy strength as an Army intelligence officer in Vietnam in 1967-68.

Graham's efficiency reports gave him top grades in everything but tact. One rater called him "by far the most capable military intelligence officer I have met in 20-odd years in the field."

According to trial records, however, some of his colleagues disagreed. "Graham was and is infamous in the intelligence community as a man who would take whatever analytical position he thought would bring the greatest rewards from his superiors and pursue that position doggedly, or change it for another if expedient, regardless of facts, logic or analysis which indicated a contrary conclusion," said Richard D. Kovar, a 30- year CIA veteran whose duties in 1968 included numerous reports and memoranda concerning Vietnam.

In a 1983 affidavit, Kovar charged that Graham was "an upward-climbing careerist who let nothing and nobody stand in the way of his grandstanding efforts to win the favorable attention of his superiors."

Graham shrugs off the criticisms and adds that other witnesses had "some pretty nice things" to say about him.

"I am not tolerant of bad work," he told a reporter. "So you can believe there are a lot of officers that don't like me . . . No, I'm not, I never have tried to pretend to be, a nice guy."

The criticisms of those who consider Graham an opportunist seem simply to bounce off. He insists that he's on the right track. The mutual assured destruction strategy had bothered him, he says, as a soldier, for many years. "You know, if Americans are frying under a nuclear attack, we're supposed to say, 'Don't worry about it, folks, we're out to fry a bunch of Russians.' That really runs very contrary to the military ethic."

GRAHAM'S training in self-defense started early. His grandfather, an Oregon sheriff, once slammed him across a cabin for "getting whipped" by another boy. Graham lived with the man for a couple of years when he was a boy. After that first thumping, he says, "everytime I came back to the cabin after that to tell him I'd been in a fight, I told him I just whipped the hell out of the other guy, no matter what happened. I wasn't going to catch it again."

Graham's parents lived in Medford, in adjoining Jackson County, and when he got back there, he recalls, his fame as a pugilist, proudly commemorated in letters from grandfather, had preceded him.

"My little brother had lined up fights for me all over town," he remembers. "I had to fight every kid in Medford."

When it came time for college, Graham's father, a roughriding cavalry sergeant, dreamed of West Point for his son -- and worked for it. A "yellow dog Democrat," Pat Graham pinned his hopes on the Democratic candidate who had promised, if elected in the 1942 campaign, to send young Daniel O. Graham to the United States Military Academy.

The Republican candidate, Mathew Harris Ellsworth, won. "Dad was in despair," Graham says. For him, "my going to West Point was like me going to heaven or something. So I said, 'Well, I'll try the guy who won.' Dad said, 'Ah, .. blankety-blank Republican.' I said, 'Well, I'm trying anyway.'

Ellsworth gave him the appointment after Graham came in first on the civil service exam the candidates took. The only trouble was he came up a fourth of an inch short of the minimum 5-feet, 6-inch height requirement.

The congressman stuck with him. "He went to the surgeon general and said, 'Oh for God's sake, he's only 18, he'll grow a quarter-inch.' He got me a waiver." Graham never grew that quarter-inch, and he got stuck in "the Runt Company," but he graduated from West Point on wartime- acceleration in 1946, three years after entering.

Graham was converted to Catholicism not long after that, during a stint at parachute training as a second lieutenant. "I sat by a priest at a ball game once and we had a couple of beers," he explains, "and the first thing you know, I became a Catholic. I was afraid the damn chute wouldn't work. Harrh! Harrh!"

He got into intelligence work in the 1950s after a series of courses at Russian language and intelligence schools, and subsequently came to take a dim view of the liberal, Eastern establish- ment that predominated at agencies like the CIA.

The general left DIA in 1976, having decided to retire the previous fall because President Ford fired Defense Secretary James R. Schlesinger. "I'm a Schlesinger man," Graham said.

He celebrated civilian life with a plunge into politics, running as a GOP-backed independent for the Arlington County Board of Supervisors against an incumbent backed by the county Democrats and Arlingtonians for a Better County. One of the issues in the hard-fought campaign became Graham's controversial presidency of the Wakefield High School PTA in 1970 when he stirred opposition with his attacks on "permissive ideology" at the school. Graham says he rolled up more votes than previous winners, but still lost the election by about 4,850 votes.

That same year, 1976, Graham also worked with Schlesinger as a military adviser to Ronald Reagan. "Even back then," Graam recalls, "Ron Reagan was asking a very fundamental question. He was saying, you know there's got to be some better way to deter a nuclear war than, as he described it, two guys with pistols pointing at each other's head . . . "

Since then Graham has made statements that lead some to understand he thinks nuclear war winnable.

"Damn weapons are awesome. No doubt about it," he said in a 1980 interview with Rolling Stone. "But they are not absolute by any means. You can escape the effects of nuclear weapons. We have had the great bulk of the population believing that if nuclear war occurs, the world will be a burned-out cinder drifing through space. That's sci-fi rubbish."

Asked if he was arguing that nuclear war is feasible, Graham, according to Rolling Stone, replied: "If, in fact, nuclear war could obliterate countries, it would be unfeasible. But the fact of the matter is, that's not what would happen. The fact is, you can win a war with nuclear weapons. Highly destructive war indeed. But the Russians, because they've paid some attention to holding down damage, would in fact take fewer casualties in a nuclear war now than they took back in World War II."

In an interview, Graham confirmed making the remarks, but added that "the only thing they left out of that is when I answered that question, I said the United States can win a nuclear war, certainly with Mexico. They leave those little things out . . . As a theoretical thing, nuclear war is winnable. As a reality, given the numbers of weapons now, no. But they ask it in terms of theory. That's why the Mexico thing is important. I said, sure we can win one -- with Mexico. So you know, don't throw this up as a total truth. Nuclear war is not winnable . . . It was winnable by us up until a certain point . . . probably until '68 or so, we could have won a nuclear war. With Russia."

Rolling Stone writer James Ridgeway says he doesn't recall Graham'saying anything about Mexico. "I think I would have remembered that," Ridgeway says. "In fact, I would have used it."

SDI SUPPORTERS include a number of big names, including Dr. Edward Teller, the physicist who played a leading role in development of the hydrogen bomb. Teller favors a different technology, a nuclear-powered X-ray laser, but he credits Graham as a fellow pioneer.

"While I might disagree with Danny (on some points), he has spent more than a few days (on the subject)," Teller said in a telephone interview. " . . . SDI is what we need in order to survive and have peace. The Soviets are doing it and they are screaming bloody murder about our doing it because they don't want us to spoil their monopoly."

The idea of a space-based defense, really a collection of ideas, has its prominent critics, too, especially over the notion that it will serve to protect the civilian population. Schlesinger declined to be interviewed about Graham, but he is skeptical about a Star Wars defense.

"The idea of a space-based defense is, as one writer has described it, 'half Buck Rogers and half P. T. Barnum,' What the president is talking about, he added, is nothing less than "a shield over this country to protect the population. That is where it gets its political clout, and it is almost certainly not going to happen."

As the summit between President Reagan and Soviet leader Mikhail Gorbachev has approached, however, Graham, for one, seems less concerned by such objections -- and less apprehensive that Reagan will make some sort of concessions on SDI that "kills it indirectly -- by making it impossible to carry out the necessary tests or to make the necessary deployment decisions."

In Graham's view, the biggest obstacle to the program is the Antiballistic Missile Treaty of 1972 and in his view, it is time to declare that "a loser" nstead of straining to interpret it in a way compatible with Star Wars.

Similarly, the unpaid marshal of High Frontier (he says he does not draw a salary) is not at all impressed with Soviet protestations about the program. It has been criticized in part because the United States, as part of its strategy of defending NATO allies against conventional attack, has never renounced the possibility of a nuclear "first strike" in response. Star Wars, the Soviets claim, will just encourage the United States to take that first step.

Responds Graham: "I don't think the Soviets be- lieve that for a minute. If we ever thought a first-strike capability was useful to solve our problems, they would have been blown up a long time ago when they simply couldn't retaliate -- when we had a monopoly or a horrendous superiority and they had practically no way at all to touch the United States. I think they know that."

At the moment, Graham seems just asbusy in his new role as chairman of the Coalition for the Strategic Defense Initiative, a group he organized this summer to help counter the "severe attack" on the program from various quarters.

The Coalition includes more than 100 organizations, from Accelerated Christian Education to Young Americans for Freedom, and more than 60 members of Congress, most of them Republicans. Its most visible message is a 30-second TV commercial that began playing in Washington in September and is expected to fan out to a 30-market peak before the summit.

It features the Astrodome concept of Star Wars, the same notion that Schlesinger has denounced as "half Buck Rogers and half P. T. Barnum." The commercial begins with a child's crayon drawing of a family outside their home under a big sun while a little girl can be heard asking her father "what Star Wars is all about."

She goes on to say that her daddy told her "that right now we can't protect ourselves from nuclear weapons and that's why the president wants to build a peace shield. It would stop missiles in outer space so they couldn't hit our house."

As she talks, a crayon-line dome appears over the house and family; missiles crash into it and are destroyed, and the sun starts smiling. The "Peace Shield" turns into a rainbow.

"When I first read the script, I said, 'Oh God, this will never do,' "But I must say, I'm thoroughly sold. It's a powerful piece . . . It's dynamite. It's dynamite."