His Closest Aide, Her Closest Friend : BEHIND THE SCENES In Which the Author Talks About Ronald and Nancy Reagan . . . and Himself <i> by Michael K. Deaver with Mickey Herskowitz (William Morrow: $17.95; 272 pp., illustrated) </i>

A couple of years back, Mike Deaver was having lunch in Paris, at Maxim’s, with Pierre Salinger, once John F. Kennedy’s press secretary, later an unsuccessful Democratic Senate candidate in California and, now, a correspondent for ABC News.

“When you ran against George Murphy, I was a kid with the Republican Party, and one of my jobs was to follow your campaign. Whenever you stepped out of a car at one of your rallies, I handed you a cigar,” Deaver told Salinger.

Deaver’s recollection of his role as a political rookie in that campaign, told in “Behind the Scenes,” continues:

“Out of courtesy or habit, he always jammed it into his mouth. Virtually every picture you saw of Salinger showed him with a cigar in his face.”

The cigar provided an unflattering picture of Salinger for the newspapers, and the story provides us with a not particularly flattering picture of Deaver, learning at an early age the impact of the political image.

The yarn, related with gusto by the author, introduces us to Michael K. Deaver, who during the formative years of Ronald Reagan’s political life, and indeed during the most important years of the Reagan presidency, was as close as anyone, save Nancy Reagan, to the 40th President of the United States. And it raises a question: If this was Deaver’s introduction to the American political process, indeed an introduction about which he is evidently pleased, what does it say about this man and the current occupant of the White House?

Deaver entered the White House with Reagan in 1981, taking the title of the deputy chief of staff. But, in reality, he was an equal partner in a triumvirate that also included James A. Baker III, then the chief of staff and now Treasury secretary, and Edwin Meese III, then the counselor to the President and now the attorney general.

He left in the spring of 1985, to set up a public relations business in Washington--an endeavor that soared to starry heights ($4.5 million in billings in less than a year, he writes) and then quickly plummeted, in the wake of multiple investigations into whether he traded improperly on his close ties to the Reagan Administration. Now, Deaver awaits sentencing after being convicted of lying to a grand jury and a House subcommittee--charges he seeks to refute in a penultimate chapter in the book.

But in “Behind the Scenes,” written with biographer Mickey Herskowitz, we have an engaging book valued not for its look at Deaver, but for Deaver’s account of the Reagan White House and, by extension, some of the pressures that play on any President in the late 20th Century.

In just such anecdotes as that tale about Salinger and the cigars, told in a straightforward manner, Deaver opens a window--revealing details about his own life, which has been devoted for two decades to the political glorification of Ronald Wilson Reagan. But more significantly, he gives us a good window on life in the West Wing--the business end--of the White House and in the Reagan household itself, where we can see the interaction between Ronald and Nancy Reagan, and the considerable impact she has on his stewardship of the Oval Office.

In the end, we find a President who--not surprisingly after the revelations of the Iran-Contra scandal--cares little for the details of his high office, does not like to work very hard and, in Deaver’s words, “came to office at a time when the perception of what was done often mattered as much as what was actually done.” But we also find a President who is portrayed as caring deeply for the people around him, willing to overlook their transgressions, and who remains a hopeless romantic.

Deaver’s effort is poignant but simplistic at times in its portrayal of just how much Ronald and Nancy Reagan depend on each other. Asked what his wife really means to him, Reagan “said, softly, without hesitation, ‘I can’t imagine life without her’,” and self-serving at other times as the author tells us just how much the Reagans depended on him. But “Behind the Scenes” is strongest not when this one-time senior White House official is delivering a sermon about life in the Washington whirl, but when he uses very specific accounts, including direct quotations, to bring us within inches of some of the historic events he witnessed and the human element in the drama.

After the gripping hours at midday on Jan. 20, 1981, when Reagan was inaugurated, the defeated Jimmy Carter left town, and the American hostages held for 444 days in Iran were flown out of Tehran, the new President commented to Deaver: “Did you take a close look at Carter? What a terrible day this must be for him.”

Individual sentences, even full anecdotes, taken alone and out of context, are not always so complimentary to the President:

--”. . . he tends to be rattled by his own sudden, blind anger,” Deaver writes of the President.

--Or, the now-often-told story about Deaver’s waking Reagan on the morning of his first inauguration: Deaver tells the President-elect it is 9 a.m. and “you’re going to be inaugurated in two hours.” (Deaver was off by an hour--the inauguration was at noon, but never mind). Reagan’s response: “Does that mean I have to get up?”

But more often, these snapshots present us with a friendlier view, in this case intended to demonstrate that the President could keep things in their proper perspective:

--Deaver tells about arriving at the White House at some ungodly hour, going through a couple of meetings, and then heading for his first meeting of the day with Reagan--who has rarely arrived at work before 9 a.m. What did he find? “The President would be in the Oval Office, with his dog, trying to teach him obedience lessons.”

Reagan would “pretty much” ignore Deaver’s suggestions that it was time to get down to business. “Finally, in frustration on that particular morning, I said, ‘Mr. President, you need to get that dog out of here. He’s going to end up pissing on your desk.’

“Ronald Reagan looked up and said, ‘Why not? Everyone else does.’ ”

Everyone, perhaps, but Mike Deaver.