Johann Hari: So that's OK then. It's fine to abuse young girls, as long as you're a great film director

So now we know. If you are a 44-year-old man, you can drug and anally rape a terrified 13-year-old girl as she sobs, says "No, no, no," and pleads for her asthma medication – all according to the victim's sworn testimony – and face no punishment at all. You just have to meet two criteria – (a) you have to run away and stay away for a few decades; and (b) you need to direct some good films. If you do, not only will you walk free, there will be a huge campaign to protect you from the "witch-hunt" and you will be lauded as a hero.

Roman Polanski admitted his crime before he ran away and, for years afterwards, he boasted from exile that every man wanted to do what he did. He chuckled to one interviewer in 1979: "If I had killed somebody, it wouldn't have had so much appeal to the press, you see?

"But... fucking, you see... and the young girls. Judges want to fuck young girls. Juries want to fuck young girls. Everyone wants to fuck young girls!"

But this is not enough, it seems, for the Swiss government to return him to the US to face trial. They have found a legalistic loophole that enables them to let him go – while admitting "national interests" may be a factor. This may be a reference to pressure from neighbouring France to free their citizen. As a Swiss citizen, I think I can say without being offensive, we all remember the bargains Swiss governments have made in the past to preserve their "national interests". This is in a long tradition of helping criminals and calling it Swiss hard-headedness.

The campaign to release Polanski has leeched into the open a slew of attitudes I thought were defeated a generation ago. Whoopi Goldberg said it wasn't " rape rape".

Others hinted darkly that she wasn't a virgin. So if a 13-year-old has been abused before, she's fair game for all future rapists? The French philosopher Bernard Henri-Levi, who led the campaign, said a little bit of child molestation isn't his problem when Great Art is at stake. He wrote: "Am I repulsed by what he got up to? His behaviour is not my business. I'm concerned about his movies. I like The Pianist and Rosemary's Baby."

That's worth saying again – this campaign was led by a man who thinks the drugging and raping of a child is "not my business", when compared to a film about Satan inseminating Mia Farrow.

The novelist Robert Harris, who is a friend of Polanski's, said: "It strikes me as disgusting treatment." He wasn't talking about the child-rape. He was talking about the attempt to punish the child-rape. He said Polanski was being subjected to a "lynch mob"? Where is this lynch mob? All I can see are people patiently suggesting the law should be enforced and he should be given a fair and open trial. This is the opposite of a lynching: it is sober justice.

Do these defenders of Polanski understand what they are saying? Harris has four children. If a great film director drugs and rapes them tomorrow, will he call the police, or will he say it would be "disgusting" to do so? Would he say the police and prosecutors trying to protect his children were a "lynch mob"? If the rapist ran off, would he say that after three decades on the run (boasting about his crime) he should walk free?

Now the campaign has succeeded. So congratulations to Whoopi and Bernard and Robert: an unrepentant, bragging child-rapist won't face his day in court, thanks in part to you. Have fun at the victory party. But you may want to leave your daughters at home.

Follow Johann Hari on Twitter at www.twitter.com/johannhari101