ZBIGNIEW BRZEZINSKI walked into Susan Clough's office the other morning; and with a very solemn look on his face, he handed her an AP news digest advisory.

Listed as one of the top stories to watch for on the upcoming day was this

"WASHINGTON - Major story containing significant revelations of Susan Clough, President Carter's personal secretary, will be carried tomorrow. This story is to be given flash priority."

It was only after several agonizing mements that Clough, who only the day before had been interviewed by The Washington Post, realized that it was a joke. A joke that she in turn played on the President, showing him the advisory. And the President, too, had an uneasy moment before he caught on.

But though she laughed, Susan Clough said later, "I never thought I would have anything in common with Lester Maddox, but I turned brighter red than I ever saw him."

Part of her concern was for her image with she guards carefully. And understandably so. Because Susan Clough has a unique problem.

She's 32 years old. She is blonde, very pretty and single. And she is, except for Rosalynn Carter, the person closest to the President of the United States, certainly in physicaly proximity.

Naturally, this has led to speculation, not only about her relationship with the President but about her social life in general. And though she understands the speculation, it still bothers her.

"I don't like to hold myself on the image people have of me," she says, "I don't perceive of myself as a physically pretty or beautiful person.

"Yet I think when I first came here I found myself wondering if people were going to put me in the role of Elizabeth Ray, not only with my boss but with the staff. I was really curious about it. But there was none of that. If there had been, I would have dressed like a school marm."

She is aware, however, of the winks and insinuations that continue to prevail, not only among the staff but also the press, about her relationship with Carter. Her first reaction is utter amazement. "I don't think Jimmy Carter has ever had an affair with anybody but Rosalynn," she says. "And that makes me feel good. Certainly now that he is President he doesn't have much opportunity; but when he was governor, he had much more opportunity. But he would never . . . never . . . " she repeats adamantly.

Then she becomes indignant. "Why is it so strange to be young, attractive, capable and intelligent?Why is it so hard to be all of those things?

"Regardless of the other qualities. If you're attractive, people make passes at you. If you're charming, beautiful and intelligent, then you're suspect. In my situation, I'm suspect." An Audible Hush

It is late one afternoon, and Susan Clough ushers a guest into her small office in between the Oval Office and the President's smaller, cozier working office. She is dressed in a brown silk patterned blouse, a rust skirt, brown shoes. Her blond hair is neatly clipped back away from her face. She is crisp, efficient and stylish.

Just as she is returning to her office, she notices Tim Kraft, Carter's appointments secretary, coming upstairs.

"I don't believe you," she teases him, then introduces him as the President's "former" appointments secretary. it seems that Kraft had been 10 minutes late for his haircut and had forced Carter to wait 10 minutes for his.

She gives a small tour of the Oval Office and hangs a visitor's coat inside the President's closet in his working office, a soft yellow room with down-filled sofas and pretty American impressionist paintings on the wall.

She explains that President prefers to work in this room, because it is more comfortable, and that he only uses the Oval Office to receive guests. "Also," she says, "it's easier, because he doesn't have to turn all the papers over on his desk when he has anyone in. You know, a lot of people are very good at reading upside down,"

She seems very comfortable in her own yellow office, with a record player prominently placed on the bookshelf near the door." Treemonisha" is playing - her selection, as are most of the selections that Carter listens to throughout the day.

There is an atmosphere of quiet, a sort of audible hush, inside the Presidential offices, which provides an almost churchlike ambience. At first one might interpret it to be the awesomeness of the office. But it soom becoomes clear that the atmosphere is not awesome at all. It is just quiet. And part of the reason is that Susan Clough speaks in a soft Southern accent - not heavily Southern, but still there. In fact, she has the say way of speaking and tone of voice as her boss.

So with the two accents, the deep plush carpets, the down-filled sofas, the soft lighting and the classical music playing in the background, it is almost hypnotic.

But nobody's asleep. It's just their way of doing things. Susan Clough is very organized, her desk is clean, her files straight.

The phone rings, she answers it in a soft voice. Nothing ruffles her. One gets the impression nothing would, at least during office hours.

She talks easily, openly, candidly about herself and her life as though she had been doing interviews all her life. She seems confident and sure of herself, but her reserve indicates a certain fear of seeming vulnerable. She is very feminine; yet beneath that softness is an almost Germanic sense of determination, singlemindedness and strong will. The one thing anyone would have to say about Susan Clough after spending any time with her is that she is a grownup. She is mature in her behavior. She is not a whiner or a complainer. She knows what she wants, and she knows how to get it. Professionally, at least.

Susan Clough wanted to be the secretary of the President of the United States - and she got the job, winning out over Maxi Wells. Carter's fulltime traveling secretary during the campaign and the one expected by many to inherit the coveted spot in the White House. But Clough was very close to Jody Powell, who had originally hired her when Carter was governor. So, when at one point during the campaign it looked as though Clough, who was based in Atlanta, might not get a [WORD ILLEGIBLE] be top job, she appealed to Powell [WORD ILLEGIBLE] Powell, it is said, is still her protector. In fact, her detractors even hint that there has been a relationship between her and Powell, but she maintains that if she were to have a relationship with a male staffer, not to mention the President, "it would have an adverse affect. I fell very strongly about dating among the staff. It would pose more problems than it was worth." Still, Susan Clough has been resented by many of the women on the White House staff and in the campaign, because they felt she had aced Wells out of her rightful job. Clough knows there is some resentment, but she has learned to live with it.

"I'm not here for a popularity contest," she says. "I know I'm not the most popular person, but I care more about my work and what my boss and my colleagues think of me. And I want people to think of me. And I want people to think of me as fair. One of my son's friends once remarked about me. "She may be stern, but she's fair." Beneath the cool exterior you can see that she is becoming visibly annoyed at the idea of criticism of her. "People are jealous, they really are," she says.

"President Carter demands a great deal of himself and of other people. I have little patience with people. I don't do as much as they can, not only other staffers but constitutents. But I think I do need more graciousness and patience. I have written a sign across my phone that says, 'SMILE.' Recently," she says, "I was in the middle of a horrendous week and a woman called about some spy problem. I had her trasferred to the Comment line. Later, I got a telegram for her, in which she mentioned having to 'brave the peach frost.' I forget that, to them, they are talking to the President's secretary. I have to learn graciousness. I'm sure some people consider me an ogre."

She laughs, "I just don't give good phone," she says, referring to Jill Clayburgh's line in the movie "Silver Streak." A Mirror Image

President Carter has just returned from having his hair cut. He finishes up his last minute desk work; and with several books and papers under his arm, he stops in Susan Clough's office and casually leans against the door to chat. They discuss what to get Amy for her birthday present the next day. Susan Clough says she'll think about it and discuss it with Rosaylnn's secretary. The President suggests may be he should get her something for the kitchen, since she likes to cook so much, Then there is a discussion of his new haircut, which is extremely good. It looks as if he hadn't had one. "I always want to get it shorter," he says, "but Jody and Ham and Tim and Susan have told the barber not to get it too short."

He is easy, affable, calm and in a very good mood, just as she is and they seem to have a truly comfortable relationship based on mutual trust and respect.

It is while the two of them are talking togethher that it suddenly becomes clear exactly why Susan Clough is Jimmy Carter's personal secretary, why she won out over Maxi Wells and every one else who may have been a contender. It is clear why she enjoys that trust and respect.

Susan Clough is almost a mirror image of President Carter. She is his female counterpart. There is something almost [WORD ILLEGIBLE] about the way they relate each other.

They have the same low-key sense of homor, the same quiet confident approach to things, the same lack of hysteria: the same slow, deliberate, determination: the same appearance of inner strength: the same display of charm and concern for the person they are with, which doesn't necessarily exude warmth, which in fact reveals a certain reserve. They are both open and frank and unafraid. And there is the definite impression that they will both got what they want regardless of who gets in their way. They both profess an impatience toward those who don't try hard enough, don't perform excellently, don't do their best. There is a no-nonsense quality about both of them. They even look alike.

But the most interesting trait the Clough has iin common with Carter is an intangible end, it is that equality that has confused and frustated. Carter observes since he first appeared on the national scene. It is that quality that keeps the observer from getting a handle on either one of them. It is impossible to read Susan Clough, to categorize her, and one comes away from a long visit not being totally convinced that she is either the sweet, sensitive, vulnerable woman she seems to be, or, indeed, the icy, ambitious, scheming person her critics portray. Surviving

Susan Clough didn't get this way by accident. At 32, she has been through more than most people will go through in a lifetime. which accounts for her maturity and, too, the well-hidden vulnerabilty.

She was an army brat, her father an officer in the signal corps. She moved from place to place most of her early life - until, at age 16, she met, fell in love with and married a West Point cadet who was in his last year. She gave birth to a son before her seventeentth birthday she is now nearly 16 and is over 6 feet tall. The next year she gave birth to a daughter.

"I'm sensitive to having been married at that age," she says now. "Especially when I look at my kids and think they are almost the age I was then. At that time I don't think I felt I was an adult, but I was very mature. I didn't think it was that unusual."

Her husband was assigned to Vietnam, and she used the opportunity to finish high school and attend college in Fresno, Calif., while waiting for his return. After he came back, she realized that the marriage wasn't going to work and she walked out.

"I believed in marriage then. To me, divorce meant hurting someone. But two years later I was at the point where I was uncomfortable being in the same room with him. You just can't raise your children in that atmosphere."

From that time on, she says, she was the sole support, both emotionally and financially, for her two children. Her husband, who is still in the military, has since seen the children maybe once very two or three years, she says.

"After an experience like that, you become aware of what you want marriage to mean to you. But you also learn that in every marriage you end up with difficulties. If you can weather them, you end up stronger."

That period of divorcing was very hard for Clough, who by then was only 18. Her father told her she would lose every friend she had, and she she did lose some. And there was another problem. "You learn," she says pointedly, "that some of your ex-husband's good friends are too concerned that their friend's wife is well taken care of."

She was living at Fort Bragg, N.C., at the time, and in order to support her family, she enrolledd in a secretarial course and passed the Civil Service exam six weeks later. One day she was reading the Atlanta Constitution, saw an ad for a secretarial job in a law firm, applied on Monday and on Wednesday she was hired. She had never been to Atlanta before, but she moved her family down and began to work doing math forms for federal tax cases.

There were times, she says, when almost felt she couldn't make it, when she would decide that the only way to survive would be to marry someone and let him take the burden of supporting herself and her children off her. "I remember considering marriage," she says, "when I just felt so tired once or twice. But then I would think, if I'm marrying for the security of my children and in order to stop working or to enhance my financial situation, then I should have just stayed married to my husband. It's only been in the last year and a half that I've even thought about remarrying . . . If I have an achievement in my life it's raising these two children." Loyalty

Susan Clough leaves the office around 6:30 at night, turning off the music, checking the President's office to make sure he didn't leave anything important on his desk, locking her safe. Her last minute check takes only a few moments. She is modest about her work and downplays the importance of her position any chance she can get. She is also quite vague about what she actuallly does all day long. What she will say is that her main function is to draft the President's correspondence - "I don't take dictation, and he doesn't like to dictate" - and that she gives guidelines to the correspondence section. She also handles personal things for the President, as do most private secretaries and she also acts as a liaison between him and other members of the staff. She arrives between 7:15 and 7:30 every morning.

"I now either get involved in the super murdane or the super substantive," she says. But she is always quick to emphasize that "I am not a policy making advisor." "Of course," she says, "there is a time when you have discussions about things; and if there's something I feel strongly about. I'll say so. If I wanted to express my concern. I would; and occasionally he has asked what I think about something.

She says she hasn't yet addressed the awesomeness of her job; but "in essence I do speak for the President of the United States. And that can be awesome. It's a strange feeling. But I know how his mind works. I know the process of his mind, how it functions, how he addresses things, phrases things, what he would like. And that's very comfortable. Sometimes I feel very comfortable and then find myself saying, 'But your employer is also the President of the United States.' And I have to realize what that means, not to me but to other people."

She says she is political now. "I suppose I am, but I wouldn't have considered myself political before. But people have the same problem trying to fit me into a political slot as they did with Jimmy Carter. I react to things on their own merit rather than the ideology of the situation. Maybe, it's time for the Democrative party to take note."

In terms of loyalty to Jimmy Carter, Susan Clough is very specific and very sure of exactly what her loyalty means. For instance, she says, she would never have erased the 18 1/2 minute [WORD ILLEGIBLE] . "Without having a second thought I can say I would never have done that," she says. "I'm very loyal and feel very strongly about the President. And it's hard for me to even imagine, hypothetically, that he would do something wrong. I know he is not capable of it. But if he did, I'd probably go in and say something. This would distress me. My Lordy.

"If he did something illegal, then he wouldn't be the same person I thought he was, the same person I was loyal to. I may be loyal, but I have to live with my own conscience."

This is not something she has ever thought about, she says. Her major concern in her job, in fact, is to see that the President is exposed to things and that he not be allowed to stay in what she calls a "cushioned environment."

"He may be the President," she says, "but he's still a husband, a father, an employer and a friend. People say the President shouldn't be concerned about whether there are mice in the office. But in fact that's a way to divert him for a moment give him something to laugh at, give him a chance to relax. Otherwise, he will relate to things only in a cushioned environment. And that's not fair to him. That's why it's so important that Jody and Ham can [WORD ILLEGIBLE] with him. My relationship, though," she says, "is not to banter with him the way Jody and Ham can."

One of the reasons that a President's secretary can be said to have enormous power is that she is in a position to select what the President sees or doesn't see. "It's really a matter of time," says Clough. "What should he put his time to," People close to both the President and Clough say that one of her smartest and shrewdest moves is not to keep things from the President but to get things to him right away - not to use that selective power to keep things from him in any political sense.

"People talk about the President being isolated," she says, "I don't think he is. I don't think he should be. But when he deals with a small issue, like deciding who gets to use the tennis court, people make picky comments. He doesn't deal with tennis-court requests any more, but still, that kind of thing provides a change of pace for him. Don't forget this is a man who hasn't had a vacation in 10 years." Friend and Mother

Susan Clough drives to and from her office every day in a brad new Fiat. She lives in a small house with her two children just over the District line in Maryland. She decided on that location, not terribly convenient, because of the Maryland school system. The house is barely furnished - no rugs, a sofa, a random chair that doesn't match, no curtains, a few bookcases. It is clear that she is not a dedicated homemaker, and it is also clear that she hasn't had a whole lot of time to spend decorating. When she arrives home around 7 p.m., her two children are there: daughter Carol, 14, talking on the phone to the children's father, who has recently been stationed at Fort Belvoir, and son Doug, 15, playing very loud rock music. She pours herself a glass of wine from the refrigerator - "I have to have my white wine at the end of the day" - then chats with her children. She is only 16 years oder than her oldest, and her relationship with them seems a strange combination of friend and mother. She talks to them as equals yet suddenly, in an abrupt switch of tone, will insist on early hours and homework. They dicuss whether she should cook dinner for them - and decide unanimously that they would rather go out for pizza and go bowling.

They are attractive, polite and well mannered children, totally, unselfconscious.

The kids disappear, and she settles into a chair with her glass of wine and another cigarette. She smokes steadily and talks some more about her life.

"I've become very selfish over the years," she says. "I couldn't do it again, for love or money, trying to raise these children alone on $200 a month - the babies, the diapers, the ballet recitals." She rolls her eyes. "You worry because you don't want your office being upright about your having children, and yet you want to spent time with and be compassionate with your children. I have been selfish and independent and temperamental, and I don't know how the children put up with me. I've thrown plates against the wall . . .

"I even have one dented pot reserved to remind me that I need more patience. Oh God." she laughs, "you're going to think I'm a raving maniac."

Still, though she has worked half her life, she does not, she says, "consider myself as an established career woman; but I've wanted my mind to grow. Maybe it's just been a way for me to avoid having my emotions grow. I've sought mental growth rather than relationships."

Perhaps that is why she joined Mensa (the organization that requires its members to have IQs of 130 or more) while she was in Atlanta.

Her emotional fulfillment is something else again. "I don't date that much," she says, "although people joke that I left Atlanta because I've dated all the eligible bachelors there."

She says that she hasn't met that many people that interested her in more than a casual way. "Only a couple of times."

And she says that now she thinks she could handle a relationship "if I wanted to. I'm sure the person would be of an equally independent nature."

What has kept her from getting involved with anyone recently was a crushingly painful breakup of an engagement she had in Atlanta three years ago. She seems to feel emotional about it even now. "There were two times in my life when I lost a great deal of weight," she says. "Once when I had $20 a month to spend on food and I had two babies. And the other time was when my former fiance let me know our marriage wasn't going to happen." The man, a senior vice president of a stock brokerage firm, had asked her to marry him and they had gone so far as to pick out a house and let their respective children pick out their rooms. When he called if off, she says, "I was crushed. And it was about the same time my engagement was broken that my brother was shot and killed." (Her younger brother was mugged and murdered by unknown assailants, on the streets of Atlanta.) During that time, she says, "my children literally took care of me."

She also says she doesn't know how she would have gotten through without the concern of Jimmy and Rosalynn Carter. "They have really done a great deal for me" she says. "I couldn't do any work then. I was responsible, at the time, for research on Carter's speeches and public relations, and the governor and Jody saw all my mistakes and put up with me while I was pulling myself together. I would just go home very night and collapse.The kids would fix my dinner. I didn't want to date anyone, see anyone, talk to anyone. I suppose that's called withdrawal.

"Finally, with the help of Governor Carter, I snapped out of it. My finance had been going to a shrink, and wasn't drinking anymore, but he had never dealt with the problems that had caused the drinking in the first place. He told his doctor then that if he had married anyone, he would have married me. But my reaction was to keep asking myself. What have I done wrong that somebody wouldn't want me? Is there something about me I should consider changing? It was a process of examining myself. And I probably felt there was more need there than there was mutual love. But, "she says, "time does take care of its own. We were both really fortunate, or at least I was, that he didn't marry me.

"I am," she smiles, "a great rationalizer."

It is when she is talking about this subject that she seems most vulnerable, and the cool, reserved Susan Clough - "my good Germanic background" - slips away to expose someone who has known what it is like to be on the edge. Interestingly, those who knew her then say that when she had this emotional breakdown and the Carters came to her rescue, that was when the women in the Carter entourage, which later became the campaign, began to resent her, possibly because of the special attention and sympathy that she received from the Carters. It is in this vulnerable mood that she will say, "I ramble so; I do ramble on. I speak my thoughts rather than think them out first. I'm afraid I'm not very interesting." Moral Support

The phone rings and Susan Clough puts down her glass of wine, stubs out her cigarette and rushes to answer it. It is Marvin Warner, Carter's new ambassador to Switzerland, calling from Europe. He is Clough's latest friend and the most serious to date, according to her. He is divorced, 58, a Cincinnati businessman and real estate developer - and a major contributer to the Democratic party. "I like him," she says, "because he has already achieved success and he doesn't worry about making it all the time the way younger men do. He seems so relaxed about everything."

The doorbell rings, and it is Congressman Bob Krueger, one of Clough's frequent escorts, Krueger, 42, is running for the Senate in Texas, and, as it soom becomes obvious, is also a former Oxford graduate and Shakespearean scholar.

"My moral support," says Susan, letting him in, "is here." It is understandable why he would be her moral support. He is tall and calm and very quiet for the most part, except when he is spouting Shakespeare - "Her mind is like a varied opal" (of Susan) or "Thou art the soul of contentiousness" (to Susan). You could not describe him as dashing. "Safe" would be a better word.

Nevertheless, when Krueger walks in, Clough removes the clips from her blond hair, letting it fall softly forward. She takes off her shoes and curls up on her chair. She becomes flirtatious, girlish, sexy, infinitely protectable and appealing. All traces of the businesslike cool and the reserve have now completely disappeared.

The conversation comes around to the hypothetical situation of whether Clough could be married to a politician. "I just don't know," she says, "and the times I've questioned it, my friends say 'Why don't I run for office?'

What she also has thought of a lot is how Rosalynn Carter has managed it, "Jimmy and Rosalynn," she says, have only to sustain itself in difficult times for both of them to grow. Especially Rosalynn. She was a very fine governor's wife; but to see what that woman did and how she has grown since then, well, she has set standards for the staff to emulate. What attracted me to the governor then was the stimulation, the motivation, the challenge. I didn't feel that way about Rosalynn then. But now I can honestly say that there are few women I have ever aspired to be like. Rosalynn is maybe one of five.

"Not that I want to be like her, but to be able to do what she has done. That she is able to go on, not being torn apart by a public life, to maintain a sense of security with her husband and the community and to solidify the foundation of her marriage under those circumstances."

It is her respect and admiration for Rosalynn, say those who know her and the Carters, that has cemented her relationship with Jimmy. Because insiders say, there is no way Rosalynn would tolerate a secretary of her husband's whom she didn't like or felt in any way was a threat to her. She may not be in a position to choose Carter's Secretary of State, say observers, but she is certainly in a position to veto Carter's secretary. Where Will It Lead?

The evening moves on to the Yenching Palace, one of her favorite restaurants, and over moosh pork with plum sauce she discusses how she likes Washington, how it is different from what she expected. She has been, as most people are now aware, one of the few people in the Carter administration to be seen often on the social circuit.

"My preconceived ideas of what Washington would be like are as mistaken as were the Washingtonians' ideas of Georgians," she says. "Washington looked upon us as a group of Southerners not aware of or used to living the lifestyle that was enjoyed here. I preceived Washington as a group of people whose sole motivation was touching power, and to a degree that's partially true. But I didn't conceive of any way I would be able to reach out and make friends. I had conceived of Washington as artificial, I wasn't prepared to enjoy or like the people I met. In some cases that's true, in some it's not. I think," she says, "that it's evident that to have the President's secretary at their parties enhances their occasion, or to have a presidential assistant or cabinet member. They're always curious, and they think it's a way to find out personal things about the President. I hope they'll like me and I'll like them. Hope fully, we'll get past the fact that I'm the President's secretary. But I think I can tell if people like me for myself. If I have any talent, it's perceiving a great deal about people and situations I may not say it in a humble way, but it's my major gift."

Susan Clough has been in Washington now nearly a year as the person closest to the Oval Office. Yet she is still not sure exactly how she feels about it, how she sees her future. There are those who suggest she may be overqualified for the job of secretary.

"I don't know whether I'll end up being truly pleased with the job and find it a challenge, or whether I'll just end up sitting there. One problem is that there are so many other staffers and policy advisers, so that it may not necessarily be a chance to stimulate myself by achieving anything or working on anything substantial.

"I just don't know," asked me. 'What do you want to do with your life?, I'd rather not make that decision now. I have enough to worry about, I have no idea what would happen. The few times in the past when I said I would like something, those things have fallen through. When I've let things take their course, they just seem to fall in place."