The trick with propaganda is to make it look neutral and scientific. At school we were once shown a film about nuclear power in which a chirpy narrator chuckled that radiation is "all around us - in the air, on televisions. Everywhere". I can't remember exactly, but I think there followed the voice of an old woman saying "but I heard it might be dangerous" and the narrator replying "huh huh, you know, even the bomb dropped on Hiroshima contained less radiation than the average tin of shoe polish".

That way, propaganda can be one of those things, like police corruption, that is often assumed to have been dreadful 20 years ago but doesn't happen any more. So we can shake our heads at the way black people used to be portrayed in Hollywood, when they were only allowed to be maids with lines like "Oh there you go again Miss Sophie, offering us freedom an' equality an' all. Why, us simple but cheerful Negro folk ain't got time to go a-votin' and a-ridin' in streetcars, we's too busy cookin' and playin' the trumpet".

But today's Hollywood is just as ideological, as America pretends it's always been fanatical about civil rights. So in The Patriot, set in the American War of Independence, and even in Spielberg's Amistad, white America is liberal and lovely and appalled that discrimination could take place. Which makes you wonder who organised all that slavery. There must have been one un-enlightened plantation owner, before the FBI arrested him and placed him on a race-awareness course.

We can laugh at the Cold War mania of The Green Berets or Rocky pummelling a Russian. But Hollywood has just released a film called Thirteen Days, about the 1962 Cuban missile crisis, described by critics as "145 minutes of Kennedy hero-worship" and "hideously inaccurate." One of the reasons is that Fidel Castro isn't mentioned at all.

This is a new twist to Hollywood propaganda. No longer is the opposition evil and cowardly; it doesn't exist. In the remake of The Great Escape, the Steve McQueen character will announce his plan for a tunnel, and the others will say: "Well, seeing there are no Germans, we could just walk out the door."

Which is a shame, because a film about America's real behaviour during the crisis would make fine entertainment. Their attitude could be summarised by the CIA file that stated "Che Guevara is fairly intellectual for a Latino". Unlike Americans, of course, who are all geniuses like Ronald Reagan and George W Bush and would never believe in anything unintellectual such as creationism or astrology or WWF wrestling.

The head of Cuban state security documented 612 plots by the Americans against Castro, including exploding sea-shells, powder to make his beard fall out and giving him a present of a poisoned diving suit. Which makes you wonder whether American foreign policy was directed by the wily coyote, under the impression that Castro was the road runner.

All this, including the farcical invasion of the Bay of Pigs, took place with Kennedy's blessing. Then, during the "13 days" of the crisis, the British ambassador, David Ormsby Gore, went for dinner with the Kennedys, later saying: "Jackie felt that the President needed a relaxed evening, so talk of Cuba or missiles was taboo."

So as the world tottered on the verge of annihilation, he couldn't discuss the matter because his wife had said: "All I've heard from you is Cuba Cuba Cuba all week long. Well you're not spoiling dinner with your silly missiles. Men, honestly."

And while America went berserk about Russian missiles aimed at American cities, they had missiles in Italy and Turkey aimed at Russian cities. Although these could only produce American fallout which, as we know from the information films is no more harmful than a spring onion. But none of that will be portrayed in the new film. Instead we'll probably see Khrushchev helping Kennedy to search for the missiles, which have been sent to Cuba by a typhoon manufactured in an underground cave by Saddam Hussein, who is heroically captured by Martin Luther King.

Now, supposedly, we live in a new world, without evil empires, requiring a new post-Cold War propaganda. We're supposed to believe the West rules by friendliness.

Up to now this has been the American and British way of dealing with the worries about depleted uranium. We would never land anything that was dangerous on a place we were trying to protect. There's probably a training film warning soldiers that, if they get any on their hands, they ought to give them a jolly good wipe with a J-Cloth before handling vegetables. Perhaps they show a film of George Robertson proving how safe it is by feeding a depleted-uranium burger to his daughter.

But just as before, they knew all along they were bluffing. For example, I don't suppose that, when Tony Blair felt something land on his back, he thought: "I do hope that's only depleted uranium and not a bloomin' tomato, as those things can be an absolute swine to wash out."