"No man, no law, no war can stop . . . Rambo," says the two-page ad in Variety. That's for sure. The ad goes on to proclaim the new Sylvester Stallone movie a gold mine. In its first six days it took in $32,548,362 and was being shown in a record 2,074 theaters. Rambo is a monster hit.

It is also monstrous. It says, among other things, that the government sold out the soldiers it sent to Vietnam, sold them out again when they came home, knows that American prisoners remain in Vietnam and, what's worse, does not care. The villains come right out of a Ronald Reagan speech: communists and Washington bureaucrats. The former are cruel and evil while the latter are merely cruel and indifferent.

There are two things you can do with a phenomenon such as Rambo. You can call it a mere movie and ignore it or you can call it a cultural phenomenon and wonder what it all means. Since the mere movies Clint Eastwood once made are now touted as the precursors of resurgent conservatism, it is probably wise to look deep in the mournful eyes of Sly Stallone and ask what he's selling that so many seem to be buying. It's more than action; it's reaction -- a revisionist history of the Vietnam war, complete with a stab-in-the-back theory.

In the movie, Vietnam was lost on the home front. Politicians and bureaucrats conspired to cripple the war effort as they now conspire to ignore American POWs still supposedly being held by the Vietnamese. If you need a rationale for why the Vietnamese would continue to hold Americans, the movie provides it: they are evil, but not as evil as the Russians, who are -- as it is said -- the focus of all evil. In this movie, though, their focus is distinctly limited. Mostly they torture Stallone until he manages to free himself. Then, armed with a crossbow with the throw weight of an MX missile, he kills every last one of them.

What's ominous about Rambo is that several million people have already seen the movie and have, presumably, liked it. They probably accept or have no serious argument with the proposition that the Russians and their flunkies, the Vietnamese, are as irrationally evil as communists were once supposed to be. In fact, the Vietnamese themselves are caricatures out of 1960s anticommunist propaganda. They are flunkies of the Russians, and their cause is neither anti-colonialism, nationalism nor even imperialism, but raw evil. Stallone's revisionism makes no allowance for anything we've learned since 1965 -- not even the welcome the "Today Show" got in Ho Chi Minh City.

Historical revisionism is sometimes more than of mere academic interest. That was the case with Germany after World War I, and it may be the case now with us. Just asGerman reactionaries itched to refight a war they thought had been lost on the home front, some elements here seem to think that Vietnam is worth repeating -- if only to get it right this time.

That is hardly the impulse behind the Reagan administration's Nicaragua policy -- but neither is it a brake on it. In fact, there is little in "Rambo" with which Reagan would differ. Like Rambo, he has the same enemies both here and abroad and, like Rambo, he seems to have learned only one lesson from the Vietnam experience: if he's going to fight, he's going to fight to win.

The most dangerous assertion in the current wave of revisionism whose text is Richard Nixon's latest book is that the Vietnam war could have been won -- and that transplanted to Nicaragua it will be, even by our proxies. Nicaragua is not Vietnam, but neither is it Grenada. There is no reason to believe the contras could conquer the country, and every reason to believe the United States can. But then just like the Russians in Afghanistan, we would have to fight continuously to hold it. We will need a whole new monument in Washington for the names of those killed in Nicaragua.

Life is no movie, but lately the two are often confused. Pictures of Stallone as Rambo grace the cover of magazines such as Soldier of Fortune, which celebrates the movie as the long-awaited response to "Hollywood liberals." Rambo himself seems to sense that times have changed. "Sir, this time can we win?" he asks, and when told "yes" goes off to war with the expression Lassie reserved for little boys. As the ad says, no man, no law and no war can stop Rambo. Not even the lessons of history -- particularly when they're rewritten.