The infantile leftist frenzy which overcame the BBC after the second Iraq war has burned itself out. Its better journalists began fighting back after their colleagues presented the 7/7 attacks on London as an acceptable punishment for voting for Tony Blair. Justifying mass murder in Iraq was one thing, making excuses for the men who murder licence fee-payers was another. In any case, America looms too large in the imagination of broadcasting executives for anti-Americanism to become a permanent ideology. Reconciliation was always likely, but it has been speeded by Barack Obama, who for better and for worse, is a wealthy European's dream candidate.

So the BBC sent Simon Schama to the US to film The American Future, a four-part series on how the dominant themes of its history are shaping it in the 21^st century. As a good liberal academic, Professor Schama oozes disapproval. There is hardly a scene when he isn't scowling or scolding. Yet you also sense that this is the BBC's Nixon-in-China moment, when old ideological disagreements are put aside. Like an ambassador to a barbaric land, the professor hints that if Americans behave themselves, mutually profitable relations may soon be restored.

Although it is easy to pick holes in his arguments, it is always a pleasure to learn what he is thinking. However, I urge readers to renew their acquaintance with Professor Schama by buying or borrowing his book of the film (American Future, Bodley Head, £20) rather than by watching the series. Far from revealing what has gone wrong with American politics, it shows all too gruesomely what has gone wrong with British television.

I cannot overemphasise how philistine the medium has become. Media executives loathe complexity and scholarly argument. On the rare occasions they feel obliged to present either - to justify the licence fee, to give them something to boast about at dinner parties - they deal with intellectuals like a spinster confronting a sex maniac. Containment is the order of the day. The intellectual must be managed and constrained until his argument is "accessible" enough for viewers they take to be cretins to understand.