THREATS and counter-threats.

Barely have Britain and the United States extricated themselves from a messy, costly and questionable war in Iraq than both nations are flexing their muscles again over its neighbour, Iran.

In the past few weeks the US Fifth Fleet has warned it will not allow Iran to disrupt shipping – a euphemism for oil supplies – in the Strait of Hormuz. In turn, Iran test-fires its medium-range missiles, conducts naval exercises and makes clear it will have no hesitation taking action should US warships return to the Persian Gulf.

Some European countries, notably France, seem keen to fall in behind Washington's sanctions bill signed by President Barack Obama on December 31. Earlier this week French Foreign Minister Alain Juppe urged EU countries to follow the US lead in freezing Iranian bank assets and imposing an embargo on oil exports.

I'd like to think this is all bluffing and baiting, but it isn't and the outcome could be catastrophic. Time and again history has shown the imposition of sanctions can so easily drag those on both sides into open conflict. The most pressing question, though, is how we managed to get to this ludicrously volatile point in the first place.

While most of us in the West were busy with festive bonhomie, our political leaders have been blithely ratcheting up the political and military pressure over Tehran's nuclear ambitions.

I'd be the first to admit that Iran having such a weapons capability makes me a tad nervous, but then I feel much the same way about Benjamin Netanyahu's Israel having its own atomic arsenal in the region.

Surely it's naive in the extreme to believe Iran would not seek to obtain nuclear arms? It has, after all, been at loggerheads with Israel for decades.

What's more, what right is it of the Americans, British, French or Israelis to say what's good for them is unacceptable when it comes to Iran? The very existence of nuclear weapons, whoever has them – democracy, autocracy or theocracy – is always going to be cause for concern.

It was rather ironic to read in Israeli newspaper Haaretz the other day that the Israeli Defence Force, in conjunction with the International Atomic Energy Commission, has plans to close down nuclear activity at the country's reactors at Dimona and Nahal Sore should war break out.

Admittedly, you would expect such emergency contingency plans to be in place, and the report doesn't single out Iran as the only principal threat, but coming as it does at this precise moment, it's both a reminder Israel has long since had the bomb and another terrifying indicator of what could unfold if the current escalation in the confrontation with Iran is not checked.

Reading the Haaretz story, I couldn't help being reminded of similar accounts doing the rounds of the Israeli press back in 1991 just before Iraq launched its Scud missile attacks against Tel Aviv and other cities at the start of the first Gulf War.

Living in Jerusalem, as I was then, rarely a day passed without some disquieting story about Iraq's chemical and biological missile threat and what Israel's "total" response would be should Saddam Hussein be foolish enough to opt for such weapons of mass destruction. Put another way, these things can so easily and rapidly shift to a tipping point that it is near-impossible to reverse and the outcome of which is anyone's guess.

All this sabre-rattling, especially by Washington, is of course only partly to do with Iran getting its hands on nuclear arms. Two other factors are key to what's happening in the Persian Gulf right now. Think US presidential election and the fact 40% of the world's oil supply is transported through the Strait of Hormuz and you'll see what I'm getting at.

Now is no better a time for Mr Obama to show America's powerful pro-Israel lobby he's on side when it comes to tackling the Iranian "threat".

On the other hand, now is not a time, given Western economic woes, when the US is prepared to stand back and have Tehran call the shots on who turns the oil supply tap on and off.

Whether Iran really wants a fight is another matter too. Any conflict would only serve to block the oil exports and revenues that are its own economic lifeline, while the country's leaders President Ahmadinejad and Ayatollah Ali Khamenei have internal political problems of their own.

Yes, Iran has been stubborn over international efforts to bring it to heel over its nuclear programme but historically – even under Mr Ahmadinejad – it has nevertheless shown itself willing to negotiate in the deepest of crises. Some analysts suggest this is still the case and, despite the bellicose rhetoric, the regime is open to talks. Not that you would think so listening to some of the more hawkish political elements in Washington and Jerusalem.

Interestingly enough on this occasion, it has been senior figures within the US and Israeli military-intelligence establishment that have been among the most vociferous in urging caution over plans to attack Iran.

The latest to add his weight to the belief the cure of an all-out strike against Iran's nuclear facilities might be as bad as, if not worse than, the disease itself came from Tamir Pardo, the chief of Israel's Mossad spy agency.

Speaking in Jerusalem this week, Mr Pardo admitted Israel was using covert means to foil Iran's nuclear ambitions, but that if the Islamic state actually obtained such weapons it would not necessarily mean the destruction of the State of Israel.

When military chiefs of staff and senior spies are urging caution, it strikes me as time to stop and think. Not so, it seems, within the ranks of politicians. Throughout the brinkmanship, warmongering and threats of the current crisis you would be hard pressed to find any cogent and significant voices of reason.

This month Britain – as part of the EU – must decide whether to join the US in imposing an embargo on Iran's oil exports. Should it choose to do so, it may only be one step away from marching to Washington's bellicose drumbeat and open conflict with Iran. We have been here before, remember. This time it's imperative that sense prevails and Britain steadfastly refuses to be cajoled, pressured or duped into another Middle East war.