With tough new sanctions in place, further measures threatened by Iran, naval forces mustering in the Persian Gulf, and state-sponsored terrorism ongoing, we are on the brink of a military conflict. Israel, at this very moment, is contemplating whether to undertake a strike. This would be calamitous, and could lead to regional war. What is desperately needed is a fresh assessment of the situation. The west's approach of sanctions and sabre-rattling are yesterday's failed policies. The fact we are once again on the cusp of conflict is testament to that failure.

My motion today therefore calls for the government - and, by implication, the west - to rule out the use of force in order to reduce tensions and bring us back from the brink of war, and to redouble diplomatic efforts. By ruling out the use of force - except, of course, in self-defence - we can reflect on some of the inconvenient truths which the west chooses to ignore, and the need for a fresh approach.

The catalyst for the most recent round of condemnation of Iran has been the IAEA's latest report. However, close reading of the report reveals no 'smoking gun'. There is no evidence of attempts to produce nuclear weapons, or of a decision to do so. Much is made of western intelligence reports. But Iraq should have taught us to be careful of basing major foreign policy decisions on secret intelligence.

A second inconvenient truth relates to the usual depiction of Iran as intransigent and chauvinistic in her foreign policy. Western governments too easily forget that Iran is not totally at fault here. There have been opportunities to better relations between Iran and the west which the west has spurned. We forget Iran expressed solidarity with the US following 9/11, and that attempts were made to develop contacts during the early stages of the Afghan war. Her reward was to be declared part of the "Axis of Evil" by President Bush. This led directly to the removal of the reformist President Khatami. Despite this, further attempts at cooperation followed in the run-up to the Iraq war, and these were similarly rebuffed.

I am not an apologist for Iran. No-one can agree with her human rights record, or her sponsoring of terrorism beyond her borders. But these are not arguments for military intervention. Rather, I suggest no-one's hands are clean in the region, including our own particularly after the invasion of Iraq.

The argument is advanced that, should Iran develop nuclear weapons, this will lead to a nuclear arms race in the region, but without the safety mechanisms that existed during the Cold War - and this could lead to nuclear escalation. I do not accept this argument.

There is no reason why the west's adherence to the theory of nuclear deterrence should not be equally valid in other regions of the world. Despite the rhetoric, there is no evidence of irrational behaviour by Iran. This view was re-enforced by the Israeli defence minister last year. Meanwhile, other countries in the region, such as India and Pakistan, have fought wars and yet shown nuclear restraint. Only one country has ever used nuclear weapons in anger.

We are then told it is naïve to rule out the use of force, that all options must 'be left on the table'. But I suggest pursuing a policy which has clearly failed is naïve. It has brought us to the brink of military conflict.

What compounds the error of this approach is that most agree a military strike would be counter-productive. It would unite Iran in fury and perhaps trigger a regional war. It would not work - a fact the US defence secretary has recently highlighted. Furthermore, knowledge cannot be eradicated by military intervention. There are even influential voices from inside Israel against a strike.

Yet, despite this, the present policy is to refuse to rule out the use of force. Such a policy is not only naïve, but illogical: we are keeping an option alive which all know would be a disaster; against a country which chooses to ignore it; yet this option heightens tensions and makes a peaceful outcome less likely. It is a nonsense.

A fresh approach is required. Israel will not attack Iran if Washington objects. Now is the time for the US to make clear to her ally that force should not be used. Ruling out the use of force would have the immediate effect of reducing tensions and making conflict less likely. This would lessen the chance of another accident, such as Iran Air 655, which could in itself trigger a conflict. Such a policy longer-term would give diplomacy a greater chance of success.

We need to better understand and engage with Iran, and offer the prospect of implicit recognition of Iran's status as a major power in the region - a status we created ourselves by our misguided invasion of Iraq which fundamentally altered the regional balance of power. There is a precedent for recognising this new status. In the 1960s, when the US presence in Asia was waning and China was beginning to flex her muscles, Nixon did not respond by denying the reality of Chinese power. His visit to China in 1972 took everyone by surprise, but it was the right decision - it was a defining moment.

I suggest the US needs to realise that this is one of those defining moments. Israel and Iran are two proud nations, both perhaps uncertain as to the best course of action. The US is the elephant in the room. It needs to put behind it the underlying antagonism of the last 30 years which defines this crisis. It needs to make clear an Israeli attack would be unacceptable, and then better engage with Iran. It is in Israel's long-term interest that this happens.

We need to go the extra mile for peace. War should always be the measure of last resort: to be used only when all other avenues have been exhausted. We have not reached this point here.

John Baron is the Member of Parliament for Basildon and Billericay. A former soldier and member of the Foreign Affairs Committee, he resigned from the shadow frontbench to vote against the Iraq war, opposed our intervention in Afghanistan, and was the only Conservative MP to vote against the Libyan intervention.