Should Britain join an American invasion of Iraq?

The Prime Minister would have us believe that to discuss the option of direct intervention in Iraq would be not only unproductive but actually wrong at this time. No decision, he argued once again yesterday, has been made. So any debate in Parliament, let alone any revelation of government thinking, would be pointless.

No it isn't. It is precisely now, before decisions are made, that we should be discussing Iraq and Parliament should be allowed its say. To wait until decisions are made will be too late. Any debate will be dismissed as inappropriate when the lives of our boys are at stake.

Of course, one of the reasons why Tony Blair doesn't want to discuss it at the moment is that he doesn't want to do anything to embarrass our relations with the US. It's still possible that the whole problem could just go away, so why rock the boat?

On this question, however, he is entirely in the hands of Washington. The Prime Minister may or may not be sympathetic himself to the idea of intervening to topple Saddam Hussein – and one suspects that Blair's natural instincts are pretty militaristic on this as on Kosovo – but when push comes to shove, he is going to commit British troops to whatever venture America decides upon.

No one should doubt the seriousness of that option. For British and American troops to go to war against another country specifically to unseat its government is a breach of every international convention. For a Western army to march deliberately on to Arab soil would arouse a wave of protest and street feeling in the Middle East whose effects could be catastrophic. And then how would you govern Iraq once you had changed the regime?

Almost everyone accepts that a change in regime would be a welcome development. On that at least Washington has the full support of world opinion, including the whole of the Middle East. Saddam is a peculiarly nasty dictator who stands in breach of over a dozen UN resolutions trying to tether him since the Gulf War. Given half a chance he would develop weapons of mass destruction with which to threaten his neighbours (although there is still some dispute as to whether he has developed any).

Nor is there anyone who thinks that the present policy of containment through sanctions and aerial patrolling is satisfactory as a long term means of controlling the beast. It has kept him caged but at immense cost in civilian lives and Arab public opinion.

But it is a huge jump from concurring on that to taking direct action to bring him down. All the considerations that prevented the Allies bringing the Gulf war to a successful conclusion in Baghdad still obtain, even more so. In contrast to its experience in Afghanistan, the US cannot use air power alone to change the balance on the ground in favour of opposition forces. There is no Northern Alliance ready to take over Iraq.

There are the separatist forces of Kurds in the north and the Shia in the south. But then you are in the game of dismembering Iraq to the consternation of America's allies Turkey and Saudi Arabia. The democratic opposition is weak and divided. Everything that the Allies have done so far to contain Saddam in the way of sanctions and air strikes has served to increase his power and his standing as a victim through the Middle East.

And all this is quite aside from the morality of intervening directly to topple a regime because you dislike it. The Allies didn't do that even in the case of Slobodan Milosevic.

It is the practical problems rather than the moral ones that hold back Washington at the moment. If it could have found effective allies on the ground, it would have sent in the bombers months ago. It would still hope, no doubt, to do a deal with the generals in Baghdad to topple their President or to assassinate the man, would that were possible. But if it is not, and if Saddam should still prove unwilling to allow in UN inspectors (as seems to be the case), then the Pentagon is prepared to send in a strike force of troops as well as missiles.

This is where the Europeans, and many in Britain, would part company with the US. It's not just a question of morality or legality, it is a question of how you define the nature of the threat of 11 September. For the Americans, the primary threat to security remains that from rogue states left by the Cold War with the resources and the technology to launch attacks on the US. Change the regimes in Iraq and Iran and you improve your safety.

For the Europeans, the security threat comes from the bitter regional conflicts exposed by the end of the Cold War. The Israeli-Palestinian conflict is the source of terrorism, not Iraq. In attacking Iraq, you threaten to ignite anti-Western sentiments throughout the Middle East.

For the Americans, the pursuit of objectives through international agreement is a secondary consideration to achieving national security. To the Europeans it has become all-important.

Tony Blair may choose to dismiss these differences as minor when set against the overarching principles of trans-Atlantic co-operation. Others would say that the issue of Iraq poses precisely the question of right or wrong that the Prime Minister said in his press conference yesterday should determine Britain's stance towards the world.

a.hamilton@independent.co.uk