Judging by the rhetorical fusillades exchanged between Israel and Iran, the threat of war between the two adversaries becomes greater day by day. Meanwhile, the chances of formal diplomacy settling the confrontation over Tehran's nuclear ambitions have receded almost to vanishing point, with the failure of the most recent talks in Moscow in June.

But scratch beneath the surface, and the picture is very different: war is not around the corner and it might not happen at all. I claim no great insight and I could be proven wrong tomorrow if Israel were to begin air strikes against Iran's nuclear facilities. Yet the case against panic remains convincing.

First and foremost, war with Iran would be a terrible option for Israel. The Iranian people would probably respond to outside attack by rallying behind their leaders and strengthening a deeply unpopular regime.

Iran would hit back through Hizbollah in Lebanon and by trying to close the Strait of Hormuz, imposing civilian casualties on Israel and a grave burden on the global economy. In Syria, Bashar al-Assad would have the opportunity to pose alongside Iran as a dual victim of a Zionist plot.

The best that Israel's air force could achieve would be to delay - not derail - Iran's nuclear ambitions. Everything that Israel's pilots destroy could be rebuilt, meaning they would exact nothing more than a relatively short interval before Iran achieves nuclear weapons capability anyway.

In fact, the military option might well be wholly counterproductive. The American, British and Israeli governments all share the same assessment of Iran's intentions: they believe the country's leaders want the ability to build a nuclear weapon, but have not yet decided whether to actually go ahead and exercise the option. After an Israeli attack, the Iranians would be compelled to take a decision - and we can all guess what it would be.

Israel's military and security leadership, including the current chief of staff, grasps all of the above. And significantly, the outlines of an implicit deal between Iran and America are emerging. This would not be a formal agreement, still less a "Nixon goes to China" breakthrough. Yet both sides might quietly decide they can live with the status quo. In other words, Iran would come close to achieving the ability to build a nuclear weapon, but refrain from actually manufacturing a device. America, for its part, would live with an Iran on the threshold of nuclear capability, provided that Tehran holds back from becoming a nuclear-armed state.

That might not be as unappealing as it sounds. Ayatollah Ali Khamenei, the Supreme Leader of Iran, is 73 and sick. Meanwhile, President Mahmoud Ahamadinejad is a lame duck who will be ousted next June. It's possible that Iran will have a new leadership in a year or two - and that could create an opening for diplomacy.

I suspect the real aim of America and its allies is to keep Iran exactly where it is - some way short of the ability to build a nuclear weapon - until that inevitable moment of political change arrives in Tehran. Hence the emphasis on direct sabotage of the nuclear programme: the goal is to slow down the nuclear clock until the current leadership disappears of its own accord.

If Iran were to make a sudden dash for a nuclear weapon, every calculation would change. But it would be the height of folly for Israel to throw all the pieces in the air by going to war in the next few months. As rational decision-makers, the country's leaders will not do anything so rash.