One of Mahmoud Ahmadinejad’s favourite tactics is to answer a question with a question. It thrusts the responsibility for whatever danger is being canvassed back on to his interlocutor and the nation he represents. When Ahmadinejad asks a US interviewer: “What need do we have for a bomb?” the message is that such a need could only arise if Iran was faced by the irrational enmity of a heavily armed super-power like, for example, the US. Or by that of an Israel, which, he pledged on Monday, Iran would never attack. The Iranian president has gone to New York determined to show that if there is any warmongering going on, it will be seen to be American, not Iranian.

When he and Bush both speak before the UN general assembly, it will be a competition in who is not to blame for any drift towards war. There is “no war in the offing” says Ahmadinejad which, decoded, means: “We’re not going to start one. But who knows what the US is thinking?” It is a fair point.

He has done a pretty good job of rhetorical pre-emption already. His US hosts look churlish for refusing his request to visit Ground Zero, forgetting the sympathy which distinguished the Iranian response to 9/11. The University of Columbia’s president, defending the decision to invite him to speak, said it was worth asking such leaders in order “to see whether they’re fanatical, to see whether they are sly”. That mean-spirited sentence is an indication of how even in a US angry and rueful about Iraq, it is still difficult to suggest that Iran has arguments and interests worth considering on their merits.

Ahmadinejad does his sabre-rattling at home, where it plays well to his supporters and even better to Arabs in the region, so his sweetness and light turn in New York has to be seen in context. President Bush does his sabre-rattling at home, too. His problem is that, at the UN, he is both at home and abroad. His speech writers will be agonising over the right balance between reasonableness and toughness. The escalating rhetoric of the last few months in both countries has similar causes.

Displacement is the key. Bush has obvious reasons to try to draw public attention away from Iraq and shift the blame for disaster in the Middle East on to Iran. Ahmadinejad’s equivalent disaster is internal. His inept domestic policies have led to discontent and even the occasional riot. In trying to regain popularity and keep the support of the real power in Iranian politics, the supreme leader Ayatollah Ali Khamenei, how useful to be able to shake his fist at the US, or to disarm US critics with a display of wit and quick thinking.

What New York should be about is creating a structure to control hostility, such as the multiple contacts, agreements, and hotlines which kept the US and Russia from going to war until the time came when there was no longer any danger. Iran and the US seemed to have made a start with the meetings in Baghdad this summer. That is the track they should both be scrambling to get on to now. — The Guardian