I INTERVIEWED Zbigniew Brzezinski, Jimmy Carter's national security adviser and now foreign policy mentor to Barack Obama, before the National Intelligence Estimate on Iran was published.

But it did not go into print until this month (in World Policy Journal in the US, Prospect magazine in Britain, Global Affairs in Russia and the Arab News in Saudi Arabia, among others). I asked Brzezinski if he wanted to re-write his apocalyptic scenario for Iranian-US relations. He didn't. "Some people with good reason fear an Iranian-US military clash before Bush leaves office in 12 months time", he says.

"There are still some people in the administration of neo-con persuasion who seem to be tempted by what I believe is a suicidal inclination to compound the Iraqi problem by some sort of military action against Iran."

Brzezinski's fear is that the Iraqi war instead of winding down could be enlarged before Bush's departure. "War is inherently dynamic", reasons Brzezinski. "There maybe some collisions, flashes, provocations, a clash with Iran, perhaps some terrorist act in the US, which can credibly be blamed on the Iranians. Al Qaeda has stated not long ago that such a collision between America and Iran will be very much in its strategic interest."

Brzezinski worries that the US risks becoming "a huge gated community self-isolated from the world... One of my indictments of Bush is that he has fostered a culture of fear in this country rather than diminished it."

For America to give Iran a military thump that it won't easily forget it is not necessary for Bush to have convincing intelligence that it is building a nuclear weapon. US-Iranian relations have soured for many reasons, not just the nuclear one, and conflict could be ignited over Iranian support for Shia movements in Iraq, the support for anti-American warlords in Afghanistan or because of an Al Qaeda initiated provocation.

The outcome would be disastrous. Muslim opinion all over the world is already extremely anti-American. It would be further enraged and the hand of Al Qaeda and its allied movements strengthened, not least some of the Pakistani religious militants who are already one step closer to capturing control of Pakistan's nuclear weapons than they were six months' ago.

So what could be on Bush's mind? What are the hard men behind him, such as Vice-President Richard Cheney, pushing for? The Middle East experts, Vali Nasr and Ray Takeyh, attempt to answer that question in the current issue of Foreign Affairs. "For the Bush administration containing Iran is the solution to the Middle East's various problems", they write. Its officials "seem to feel that in the midst of disorder and chaos lies an unprecedented opportunity for reshaping the region so that it is finally at ease with US dominance and Israeli prowess."

That such a scenario is built on what most of us would regard as a fantasy seems not to bother them. But can one really imagine Sunni Arab states will unite to support the present Shia dominated Iraqi government so as to undermine Iranian influence there? Or that Saudi Arabia will work to de-claw Hezbollah because they fear Shia primacy in Lebanon? Or that Israel and the Arabs will work together against Hamas in Palestine to thwart Iranian influence?

Well, if you believe all this it is not surprising that you also believe that Iran, with or without a bomb, can never be a constructive presence in the Middle East. Yet there is no sign that Iran, as it did under the Shah, is seeking to become the pivotal state in the region. It is not creating disorder to fulfil some misread scriptural promise. Nor is it by nature an expansionist power. Iran has not begun a war for over 200 years. When Saddam Hussein's Iraq attacked Iran, Iran was clearly the innocent party.

The Arab states may worry about Iran's growing influence, but they know a good part of the reason is Israeli intransigence with the Palestinians. Continuous and consistent pro Palestinian support has given Iran a big return on its soft power, whilst American hard power is a declining asset — there is no way that the US can maintain large numbers of troops in the region indefinitely.

With Iraq still a quagmire, with Nato partners losing the war in Afghanistan, with Lebanon in turmoil, and with very little prospect of substantial Israeli concessions to the Palestinians, this is not the time for cranking up hostility towards Iran. As Nasr and Takeyh remind us, "The last time the US rallied the Arab world to contain Iran, in the 1980s, Americans ended up with a radicalised Sunni political culture that eventually yielded Al Qaeda."

Jonathan Power is a veteran foreign affairs commentator based in London