...the West cannot simply let things drift. Military action by whatever agency cannot be written out, but will be a last resort. In the meantime, all means short of military action, including economic and political ostracism and economic sanctions, must be tried, together with the building of alternative oil pipelines to bypass the current routes of oil supply down the Gulf. And, of course, the intensification of anti-terrorist measures.

For if the West is considering military action, so are the ayatollahs. They are the sponsors of much of the insurgency in Iraq and suppliers of the insurgents' weapons. They also have intimate links with most of the world's worst terrorist organisations, including al-Qa'eda and Hezbollah. Iranians may well be the missing link for which MI5 is searching behind the July 7 bombings in London.

Moreover, while Iran has its own armoury of medium-range missiles suitable for nuclear delivery, the ayatollahs are also known to favour the placing of nuclear warheads in target cities by terrorists travelling by car or public transport. This is a bad and worrying time in world affairs.