Iran has grabbed 15 British sailors and marines and threatens to put them on trial for trespass into Iranian waters. Britain says the crew was operating in Iraqi waters and has demanded the immediate return of its naval personnel. An American commander in the Gulf is sneering at the fact the British allowed themselves to be rounded up and taken to Iran without a fight.

No doubt, the Americans would have fired both barrels just as they do in Iraq when a car on the highway gets a little too close. If the British sailors hadn�t had the foresight to refrain from escalating the contretemps, given the current fragility of relations, we could be saying hello to World War III.

A former First Sea Lord Admiral Sir Alan West explains the British position: �Rather than roaring into action and sinking everything in sight we try to step back and that, of course, is why our chaps were, in effect, able to be captured and taken away.�

The US and the EU are unreservedly backing Britain. No surprise there. But, in fact, both Britain and Iran may be acting in good faith since ownership of the waters in that part of the Shaat Al-Arab has been disputed since 1975 when Saddam Hussein unilaterally binned a treaty with the Shah.

It�s interesting that neither side is willing to make public the coordinates. What isn�t disputed is that the stalemate over this incident is turning ugly.

There are some who are optimistically expecting a replay of an incident in 2004 when eight British sailors were arrested by the Iranian Revolutionary Guard for straying across the watery divide and paraded on television wearing blindfolds. Within a few days they were released with nothing more than bruised egos.

However, these are very different times. There was little love lost between Tehran and London in 2004, but today the climate is palpably frosty over Iran�s insistence on its rights to enrich uranium under the terms of the Nuclear Non-Proliferation Treaty and unsubstantiated allegations it is funding and arming Iraqi militant groups.

Iranian and British ambassadors in London and Tehran respectively have been summoned to deliver explanations on behalf of their governments.

At first, a few underlings of Britain�s Secretary Margaret Beckett were dispatched to wag their fingers at Iranian diplomats but �brusque� doesn�t go down very well in this part of the world, so now Tony Blair has hurled himself into the fray adopting an uncharacteristic threatening tone.

�I hope the Iranian government understands how fundamental an issue this is for us,� said Blair during a European summit held in Berlin. �They should not be under any doubt at all about how seriously we regard this act, which was unjustified and wrong.�

For its part, Tehran insists the British detainees have confessed to their crime and may face prosecution.

Theories as to why the Iranians took this step abound. One idea is the Brits were taken in order to be used as bargaining chips for the return of Iranian diplomats arrested as spies earlier this year in the northern Iraqi town of Irbil, although this has been discredited by the Foreign Office.

Another is Iran wants to flex its muscles to show the world it won�t be pushed around no matter how many UN sanctions are slapped on it.

Alternatively, the Iranian Revolutionary Guard may have genuinely believed foreign forces had infringed Iran�s sovereignty. If that�s the case, in normal circumstances the British naval personnel might have been urged to retreat with a warning. But these are far from normal times.

It�s hardly surprising that Iran has gone strongly on the defensive when the US and Britain work in the UN to cause it as much pain as possible and reports from US media and military people in the know suggest Washington is poised to attack Iran�s nuclear facilities with tactical nuclear bunker-busters.

Let�s be realistic. It�s not difficult to take such reports at face value when US warships and strike forces are gathering in the area and an admiral has been appointed as the Pentagon�s top man in the Middle East.

Moreover, US officials, including former Ambassador to the United Nations John Bolton, are openly calling for regime change in Iran and it is common knowledge that Washington is funding Iranian opposition groups in the diaspora as well as ethnic separatist militias in country.

There are further suggestions that the CIA has infiltrated certain parts of Iran and may be behind a number of violent incidents.

With such coordinated hostility directed at Iran, it is hardly surprising the Iranians are hypersensitive. In this climate, any standoff could trigger a major conflict. It could be that�s exactly what Washington and its ally Israel want to see. Britain, on the other hand, has made it clear it has no appetite for war with Iran and with only weeks to go until Tony Blair kisses goodbye to Downing Street, his legacy trashed over the Iraq fiasco, it�s in Britain�s interests to deescalate tensions.

However, there is an unknown quantity in respect to Blair. We don�t know how embedded with US neoconservative thinking he really is. It could be that he would like nothing more than a go at Iran before launching himself on the talk and book-signing circuits.

An incident like this could provide ample fodder for Blair to take his country kicking and screaming toward another bloody fiasco, designed to solidify Anglo-American domination of this region and keep Israel as the sole regional nuclear power in perpetuity.

Such a war would also boost George W. Bush�s flagging approval ratings and quell the current Democratic anti-administration revolution over an exit strategy for Iraq, as well as the politically motivated sackings of eight federal prosecutors.

I can picture Bush, using his well-honed agonized expression, telling Congress how America must stand shoulder-to-shoulder with its steadfast friend Britain. For the Middle East, such a course would be disastrous. The British Cabinet must keep Blair firmly boxed. The Iranians should be advised by friendly neighbors not to rise to the bait.

And as for the Americans, I�ve just one parting sentiment. For goodness sake go home!