The surge in United States troop levels in gathering pace. As it does so, the civilian losses in Iraq continue at an appalling rate: as many as a hundred people often die each day as a result of car-bombs, shootings and other attacks. American soldiers themselves continue to fall. A relatively low level of casualties in the first two weeks of January may have reflected a reduced number of patrols, but from the middle of the month the US casualty rate soared. In the four weeks to 24 January, eighty were killed and 400 wounded.

There is now little expectation in Washington that the surge will have a radical effect, and indeed the notable current tendency is radically to curb expectations. President Bush's nominee to replace General John Abizaid as head of US central command (the military operations centre covering the middle east, including Iraq and Afghanistan) is Admiral William Fallon; during his confirmation hearings in front of the Senate armed-services committee on 30 January, he was notably cautious.

Paul Rogers is professor of peace studies at Bradford University, northern England. He has been writing a weekly column on global security on openDemocracy since 26 September 2001

Two elements of Fallon's thinking were apparent. The first was to limit expectations in Iraq, and to expect any degree of success to be slow in coming, despite the reinforcements now being deployed. The second was to concentrate on curbing the power and influence of Iran, an aspect of the war that has come rapidly to the fore in Washington in the past three months.

This week, under-secretary of state Nicholas Burns warned that Iran was involved in attacks on US forces:

"We have picked up individuals who we believe are giving very sophisticated explosive technology to Shi'a insurgent groups, who then use that technology to target and kill American soldiers. It is a very serious situation. And the message from the United States is that Iran should cease and desist" (National Public Radio, Morning Edition, 1 February 2007)

Burns went on to say that the matter could be resolved by diplomatic means, but repeated the standard administration line that all options remained open including military action, specifically in relation to Iran's nuclear ambitions.

A few commentators have warned of a confrontation with Iran for several years - see, for example, Crisis Action and the Oxford Research Group. Several columns in this series have also emphasised this prospect (see, for example, "Iran, the real focus", 16 March 2006 and "Iran: the politics of the next crisis", 28 September 2006). For the most part, they have been discounted. Today, in the context of the changed mood in Washington - and even though it is an extraordinarily dangerous prospect and seems so far-fetched as to be unbelievable - the risk can no longer be ignored.

Tehran sting

What has happened is this. As the United States predicament in Iraq has steadily deteriorated, the reaction among the more hawkish opinion-formers in the US has been to insist in the strongest terms on the need for victory in Iraq, while seeing Iran as the real reason for current failures. Iran therefore must be dealt with, initially at least in terms of destroying any nuclear capability it may possess or be seeking to acquire. This objective is aided by the rhetoric of Mahmoud Ahmadinejad, especially his holocaust-denial propaganda, notwithstanding the fact that much of it is intended to deflect criticism from the mounting failures of his domestic policies.

In one sense, Iran was always the main issue for neo-conservatives: "the road to Tehran runs through Baghdad" was their mantra. Indeed there was a strong view in 2003 that the best way to deal with Iran was by installing a client administration in Iraq, secured by a substantial permanent American military presence at four large bases. Iraq would become a western bastion, with the added double benefit of reducing the significance of a somewhat unpredictable House of Saud while ensuring the Iran would know its place. In essence, regime termination to Iran's east (Afghanistan) and west (Iraq) within two years would achieve a precious strategic success: a pliant Tehran.

It has not exactly worked out like that. Instead, a Taliban revival is underway to the east and a terrible descent into violence to the west, with US forces steadily losing control. US neocons cannot in any sense consider this to be a failure of US policy; someone else must therefore be to blame, and Iran is the obvious candidate. Its culpability is both in its underpinning the evolving role of Shi'a militias in Iraq, and in its working full-tilt to develop nuclear weapons which threaten the United States's closest ally, Israel.

There are, in fact, numerous signs that the Iranian nuclear programme is in serious difficulty. But Iran's president has chosen to announce an expansion of the uranium-enrichment programme, a move calculated to raise tensions as well as (again) to divert his people's attention from domestic concerns. In a further, military initiative that could come to fruition at any time, Iran is reported to have converted one of its ballistic missiles into a satellite launch-vehicle able to lift small reconnaissance satellites into low orbit (see Aviation Week, 26 January 2007). This would be little more than a technological demonstration, but its psychological and political significance across the region would be considerable.

Iran is making progress on two other fronts in ways that annoy Washington. First, Pakistan and India have agreed with Iran a pricing formula for gas delivered to both countries by a planned $7 billion pipeline. Second, and even more of an affront, is Iran's decision to promote close economic, diplomatic and military cooperation with Iraq. This includes an offer of training equipment and advisers for the Iraqi army, aid in civil reconstruction and (most symbolically) the opening of a branch of the Iranian national bank in Baghdad (see James Glanz, "Iran looking to expand its presence in Iraq", International Herald Tribune, 30 January 2007).

In addition to his weekly openDemocracy column, Paul Rogers writes an international security monthly briefing for the Oxford Research Group; for details, click here

Paul Rogers's new book is Into the Long War: Oxford Research Group, International Security Report 2006 (Pluto Press, November 2006)

The cost of conflict

Meanwhile, the overall attitude of the Bush administration has become progressively more hardline. Its more strident comments about the threat from Iran have been accompanied by two other moves that may well be designed to prepare the way for war. As with the increased troop numbers in Iraq, these go directly against the recommendations of the Baker commission's report which called for improved diplomatic links with Tehran.

The first dates back to autumn 2006 when "Bush gave the military secret authorization to kill or capture members of Iran's Revolutionary Guard, including members of a Guard unit known as the Quds Force, and any Iranian intelligence operatives suspected of arming or supporting Shiite militias in Iraq" (see Dafna Linzer & Ann Scott Tyson, "Lethal-Force Order Justified, Bush Says", Washington Post, 27 January 2007). What is significant here is that this decision was only publicised four months later, in what appears to be a deliberate policy of preparing the domestic audience in the US for a crisis with Iran.

The second initiative is the widely publicised deployment of a second US navy carrier battle-group to the region. This initially appeared to be a temporary measure which would entail merely a longer-than-usual overlap between deployments (carrier battle-groups normally deploy for six months before being replaced, but each group has the capability to remain on station for much longer than that, allowing for a short-term doubling-up).

Now, however, it seems that the two-group arrangement is not a temporary political "symbol" but a longer-term arrangement. The point here is that having two carriers in the area at any one time allows for even more "overlap". It will therefore be quite easy to deploy three full carrier battle-groups for extended periods if required.

This is the first time that more than one group has been in the region for any length of time since mid-2003. The resources of a powerful naval force to support any action against Iran are abundantly present.

In these circumstances, the conclusion must be that a direct military confrontation with Iran is now seriously likely in the next six months, no matter how dangerous that might prove. The perils of such a confrontation remain as great as ever; they were assessed in (for example) this Oxford Research Group report in 2006:

It is clear that a full-scale US air attack on Iranian nuclear facilities and related infrastructure could do substantial damage, as well as causing hundreds and probably thousands of casualties. Even a more limited Israeli raid would have a major effect.

Equally clear is the wide range of options open to Iran in responding to such an attack - especially as its principal immediate effect would be a fundamental unifying of opinion in favour of the government (no matter how unpopular it might be in other respects).

The possibilities include:

• immediate withdrawal from the non-proliferation treaty and a wholehearted effort to develop nuclear weapons as quickly as possible - leading to further action by the United States and Israel, and a long war

• action against US forces in Iraq, through Shi'a militia intermediaries on a far larger scale than at present

• direct involvement of Iran's Revolutionary Guards in Iraq

• closure of the Straits of Hormuz, causing a steep increase in world oil prices

• aid and encouragement to Hizbollah in southern Lebanon (especially if Israel was involved in the attacks)

• paramilitary attacks on oil facilities in western Gulf states.

Furthermore, an attack on Iran would be seen by Shi'a groups in many other countries as an attack on them; this would create potential for severe disturbance, not least in Saudi Arabia and Bahrain.

Against the trend to escalation, there are fortunately many indications of serious unease by European governments at the prospect of a war with Iran. Moreover, the public mood in countries such as Britain may simply not tolerate another war. There is also a much higher level of knowledge about the risks; Crisis Action plans on 5 February to release a major report on this theme, which highlights the dangers and argues strongly for further diplomatic engagement.

The neocon tide may still be flowing in Washington, but US military action against Iran is certainly not inevitable. A pivotal influence in shaping the key decision could well be the position of the Tony Blair government in London. If one of his last actions in office is to back a US confrontation with Iran, it would be an even more grievous mistake than Britain's Iraq policy - a grim end to his decade in office, and a devastating farewell to people in the middle east whom war will affect most harshly.