Iran’s theatrically staged announcement that it has begun enriching uranium coincides with reports that the Bush administration has been updating plans for air and missile strikes against Iranian nuclear sites.

The crucial conclusions to draw are that Iran’s clerical regime cannot be easily deflected from its pursuit of nuclear weapons, and Iran’s rulers are intent not to appear intimidated by hints of an American recourse to military force. Last week’s events should lead to a reconsideration of President Bush’s approach. To set back Iran’s nuclear programme for even a short period, military strikes would have to destroy not merely scores of suspected nuclear sites, but also Iran’s air defences, airfields and missile launchers.

Bush should be asking what kinds of retaliation the Iranian regime would be likely to launch; whether the upshot would be an even greater Iranian determination to pursue nuclear weapons; and whether another US military venture in the Gulf region might not be a disaster for US interests.

Iran’s refusal to comply with IAEA requirements and to honour agreements with European partners can have harmful consequences. Iran’s refusal thus far to accept the offer of a guaranteed supply of nuclear fuel from Russia for use in Iranian nuclear plants may bring about international isolation and economic sanctions.