The men of the Black Watch, as they begin the reinforcement of the US zone in Iraq, will be experiencing a mixture of emotions. I well recall how I felt as I waited with my men of the Royal Irish before the spring offensive of 2003 and was inspired to address them on the eve of battle. Their commander will also be thinking about what is ahead. The deployment could represent, at the very least, an escalation of the war and may have far-reaching consequences for the United States, Britain and the international community.

The current conditions certainly demand immediate action. There is a pressing need to expand the coalition, to relieve the burden on America and to increase aid and encouragement to the fledgling Iraqi administration. In other words, perhaps a diplomatic offensive is called for rather than a military one.

I take the simple view: putting aside the rights and wrongs of the spring 2003 offensive, it is high time the international community and the UN put its full weight behind the stabilisation of Iraq.

The motivation for the request for British troops remains the focus of intense speculation. Is it a sop to George Bush’s re-election campaign? An attempt by the administration to persuade its allies to share the burden of combat operations, in the face of John Kerry’s assertion that the US is shouldering 90% of the financial burden and 90% of the casualties? If so, then it is cause for real concern. The shedding of British blood is too high a price to pay for the enhancement of our standing with a political ally.

A renewed military offensive must also be seen in the context of the US forces’ continued failure to win control of the rebel stronghold of Falluja and the determination of the administration to have this running sore under plaster before the presidential elections — though Bush’s cohorts would have us believe that a smooth progression to the Iraqi elections in January remains their primary objective. As a former soldier, I believe that military offensives should be based on strategic advantage and circumstance, not party political convenience.

Whatever lies behind the timing of this initiative, the need to deploy an entire battalion smacks of military miscalculation. If, as seems likely, it is not merely an enhancement of the original plan, it can only be the product of either a serious underestimation of the enemy or an overestimation of the weight and reliability of friendly forces. If the former is the case, then the intelligence services have failed once more. If the latter, there is equal cause for alarm. Whatever the reasons, though, I agree with Geoff Hoon that there can be no question of refusing the request for reinforcements once it has been made. We are in this together, and must remain together or hang separately.

The Black Watch were alongside my own Royal Irish in Iraq. They were withdrawn shortly afterwards to support infantry training in the UK, but they had hardly begun this vital task when they were called back to Iraq. Overstretch of the British infantry demanded this; there was simply nobody else. Now they are to be extended in their role. For the duration of this new deployment, they seem likely to be under American command. So what problems might lie ahead for them? It is the US Army’s proud boast that it has the capacity to act instantly and manoeuvre effortlessly because of the quality of its communications system. It is true that the US forces’ radios are the equivalent of Formula One racing cars while the British Army, badly underfunded for so long, still has to make do with 1970s Morris Marinas. As a student owner of a Marina, and someone who has spent his career with the British Clansman military radio at his elbow, I can assure you that both are crap.

The Americans will therefore need to provide signallers to operate with the men of the Black Watch so that they can speak to them on the ground and, among other things, avoid any danger of a “blue on blue” with coalition airpower, to whom British ground troops currently cannot speak.

In terms of actual command, we are given to understand that they will be under American tactical control. This essentially means that troops can only carry out tasks that have been previously agreed by the British; and they cannot be allocated new tasks by the Americans.

But whatever way you look at it they are under the command of the United States. Britain has been a junior member of coalitions before — in Korea, the first Gulf war and in this most recent Iraqi conflict — but assigning ground troops to an American formation is a departure and one which will set many precedents.

They must operate under their own rules of engagement. It was disingenuous of the Labour MP Gisela Stuart to suggest on the BBC World Service last week that the UK should not ask for “national caveats”. These are vital. Anyone who has served beyond Islington knows this — for the simple reason that the United States has not signed up to the international courts and that Britain has. Were our servicemen to be ordered by a US commander to act in a manner open to criticism of excessive zeal, they could end up in the dock in the Hague.

On the ground, British forces will face as daunting a task as their American counterparts have so clearly experienced. The area to which they will be deployed is in the traditional Sunni area of Iraq, heartland of support for the old regime and bolthole of foreign Islamic radical fighters.

Britain has undoubtedly had a smoother ride than the Americans until now. The Shi’ite southeast of Iraq has traditionally been better disposed to the coalition. But we shouldn’t forget that the traditional British approach to peace enforcement has played its part, based on 60 years of experience since the second world war and the application of the sound principles espoused during the Malayan emergency in the 1950s.