Only Parliament should decide if more British troops go to Iraq. It must say 'No'

Persistent humiliation and torture of Iraqi detainees, while their American jailers stand by laughing, besmirches us

The rule of thumb to decide whether the dispatch of more British troops to Iraq should be put to Parliament for approval is this: if the demand comes solely from British commanders, if their objective is to operate more effectively in their existing area of responsibility, then so be it. Ministers can quite properly decide this on their own. But if the request comes from the US government, or from an Iraqi authority of some kind, if it asks Britain to take on greater responsibilities, then quite different considerations apply and the matter should be the subject of Parliamentary debate.

The reason is simple. The Prime Minister has shown consistently crass judgement in this matter. He has taken us into a coalition with the US, over whom he has no influence, whose blunders, some of them war crimes, are beyond counting. I will trust Parliament, properly briefed, to make a wise decision, but not Tony Blair.

Parliament did approve the decision to go to war in the first place. There was a vote in favour of risking the lives of British troops for a specific purpose - to stop Saddam Hussein from using weapons of mass destruction on his neighbours and further afield. As the world knows, no weapons of mass destruction were employed during the invasion, for Iraq didn't possess any. So the first question that Parliament would need to establish, having once already sent troops to war on a false basis, is this: for what precise purpose would further troops be required?

Mr Blair might reply: to enhance security until sovereignty is handed back to an Iraqi government, or, more likely, to help maintain order while a temporary administration organises elections. All well and good, except the question of who exactly is requesting the reinforcement is worth teasing out.

There won't be an independent Iraq government after 1 July, that is for sure. As a recently written and promptly leaked Foreign Office memorandum put it: "We shall want to minimise the profile of coalition forces after 1 July, and get the Iraqis out in front as much as possible, particularly in patrolling and policing." No doubt colonial governors used to send similar messages back to Whitehall in the days of empire. We must get those Sikhs or Zulus or whatever "out in front".

The request for more British troops, perhaps to fill the gap created by the departure of Spanish forces from Najaf and Qadissiya provinces, is therefore likely to come, if it hasn't been received already, from the White House. The circumstances very likely may be such that the security situation remains desperate and no credible interim government can be assembled. Nor can the UN be persuaded to pass an enabling resolution. Imagine the situation as it is today only a little worse.

Presumably Mr Blair would try to make the question into a moral issue - even in the midst of a deeply immoral war. I guess he would say something along the lines he delivered in Turkey a week ago: "We will continue until the job is done.... Every time there is a terrorist incident in Iraq, or someone is assassinated, that to my mind is a reason for staying the course, not a reason for cutting and running."

Staying the course in what circumstances? I hope a Parliamentary debate confronts the unwelcome fact that being in a partnership with poorly led and badly trained American forces adds to the difficulties facing British troops. For example, heavy-handed US military tactics in Fallujah and Najaf some weeks ago fuelled both Sunni and Shia opposition to the coalition, and lost us much public support inside Iraq. And the result was that fighting was extended to the British zone. Furthermore, the horrors routinely perpetrated by the Americans in their own area of responsibility directly affect the attitude of Iraqis towards British troops.

Read what the Red Cross noted in a section of one of its reports, entitled "treatment during arrest". American troops "sometimes arrested all adult males present in a house, including elderly, handicapped or sick people.... In almost all instances ... arresting authorities provided no information about who they were, where their base was located, nor did they explain the cause of arrest. Similarly, they rarely informed the arrestee or his family where he was being taken and for how long, resulting in de facto disappearance of the arrestee. Many families were left without news for months, often fearing that their relatives were dead." Yet coalition intelligence officers told the Red Cross that, in their estimate, between 70 per cent and 90 per cent of the persons deprived of their liberty had been arrested by mistake.

This is why the Foreign Office memo so delicately observes: "We need to double our efforts to ensure a sensible and sensitive US approach to military operations. The message seems to be accepted at the highest levels but not always implemented lower down the command chain." Indeed not. The American command chain is dysfunctional.

Staying the course to do what exactly? The official answer comes pat: "Our strategic objective is a democratic, stable and prosperous Iraq, that poses no threat to its neighbours. This involves rebuilding and rehabilitating a country damaged and traumatised by years of brutality and mismanagement." How excellent. But this formulation raises the biggest question of all for Parliament to consider. Can this "job", which the Prime Minister says we will continue with until it is completed, actually be done at all by this coalition? Note that the forces of resistance are proving more effective all the time. It isn't even safe for a friendly Iraqi politician to turn up at the heavily guarded Coalition headquarters in Baghdad and hope to gain entry safely.

As we saw last week, a vehicle can be blown up under the walls of the fortress. The Foreign Office memo is pretty frank about all this. There are signs of "better organisation" by what officials describe as "insurgents" and there is a "reservoir of popular support, at least among the Sunnis". The memo goes on to observe that coalition power is precarious in some areas. This, in turn, makes the work of reconstruction impossible. Targets for summer electricity production are unlikely to be met. Think what that means for Iraq's hospitals - sweltering in the desert heat, no air conditioning, power cuts.

More serious still, and absolutely fatal to our hopes, the coalition to which we belong has lost all moral standing. The revelations, complete with photographs and Red Cross testimony, of persistent humiliation and torture of Iraqi detainees, while their American jailers stand by laughing, shame us all. It besmirches us. This we resent.

Just before the war began, two million people marched carrying banners that proclaimed "Not In Our Name". Yet this ghastly business has been done by our closest ally. We may have had our own small share in the atrocities. Oh Mr Blair, there is no "course" to stay. To think so is pure delusion. The project is beyond repair. Meanwhile, Parliament can at least state this: no additional troops.