The United States campaign in Afghanistan is winding down, but who will be its next big target in the "war on terror" remains in the realm of conjecture. Of the three chief members of the "axis of evil" that George Bush identified last week in his state of the union address - Iraq, Iran and North Korea - he dedicated most of his wrath and spoke most threateningly of that hardiest of Washington's villains, Saddam Hussein.

Yet, if Israel gets its way, the next target could be Iran. President Bush was forthright in his address: he told Tehran to stop harbouring al-Qaida terrorists and added the threat that, if it did not, he would deal with Iran "in diplomatic ways, initially". Israel has long cast the Islamic republic as its gravest long-term threat, the "rogue state" at its most menacing, combining sponsorship of international terror, nuclear ambitions, ideological objection to a Jewish state and unflagging determination to sabotage the Middle East peace process.

Israel classifies Iran as one of those "far" threats - Iraq being another - that distinguish it from the "near" ones: the Palestinians and neighbouring Arab states. As the peace process progressed, the near threats were steadily being eroded. A benefit of the 1993 Oslo accord was said to be that it would fortify Israel for its eventual showdown with its far enemies. The closer their weapons of mass destruction programmes come to completion, the more compelling the need for Israel - determined to preserve its regional nuclear monopoly - to eliminate them.

For a long time the strategy of enlisting the growing Arab peace camp against Iran and Islamic extremism from afar seemed to be working. Committed, under Oslo, to fight all forms of Palestinian violence against Israel, the Palestinian leader, Yasser Arafat, came to blows with Hamas and Islamic Jihad, and the anathemas he hurled at Iran, their ideological mentor, were all but indistinguishable from Israel's.

But now both threats have converged, malignantly, as never before. This, for Israel, was the deeper meaning of the Karine-A affair, the 50-tonne shipment of Iranian-supplied arms destined for Gaza that it seized last month. It was a "most dangerous axis", said the Israeli chief of staff, which threatened to "change the face" of the Israeli-Palestinian struggle.

As well as supplying arms and finance, Iran, the Israelis say, is developing a supervisory role over the Palestinian "terror" by the exploitation of its existing assets in the arena, mainly the Lebanese Hizbullah, and its new ones, a direct link with Mr Arafat and the Palestinian Authority, and a recently created Palestinian Hizbullah of its own.

Had the Karine-A cargo made it to Gaza, and thence to the West Bank, it could have made at least a dent in Israel's enormous military superiority. The Palestinians would no longer have been entirely helpless in the face of Israeli armoured incursions into their self-rule areas. The weapons would also have brought whole population centres within range.

Though Mr Arafat and Iran denied any part in the arms shipment, there were compelling reasons why these friends-turned-enemies should have resumed their collaboration of old. Mr Arafat's desperate need is obvious. The growing violence of the conflict and the complete failure of any country to come to the Palestinians' aid present a golden opportunity for the Islamic republic, at least for the conservative, clerical wing of its leadership. This wing has exclusive, unaccountable control over underground aspects of foreign policy, such as support for Islamist "revolutionaries" such as Hizbullah and Hamas.

Iran's president, Mohammad Khatami, and most of the reformist camp may seek to dilute the extreme anti-Israeli orthodoxy, but Tehran's foreign policy is very much an area of competition between the country's rival political wings.

The simplest way to thwart the growth of such a Palestinian-Iranian alliance would be to deny it its essential raison d'être by restoring a peace process that has some prospect of success. But it has become clear that peace is just what the Israeli prime minister, Ariel Sharon, does not want: Palestin ian violence serves him much better.

For him, the Karine-A incident provided further, dramatic justification for the undeclared but ill-disguised agenda he is pursuing in the name of retaliation and self-defence - to destroy the notion of self-determination on any portion of Palestinian territory.

But the Israelis took particular alarm at the words of the former Iranian president, Hashimi Rafsan jani, who said recently that, if Israel continues "its hellish policy of expanding its nuclear arsenal, it will eventually draw the Islamic world into the race.

Then it will be Israel, a small and illegitimate country, which will lose out and be destroyed." Impressing on the United States the gravity of the Iranian threat is a continuous Israeli preoccupation. It "must understand", said the Israeli defence minister, Binyamin Ben-Eliezer, "that this is not only a threat to Israel, but to the whole world". Tehran would have a nuclear bomb within three years and was developing missiles which could target any point in Europe.

There is no issue on which the Israelis, through their extraordinary influence in Congress and elsewhere, have proved better able to shape US policies than this one.

Quite simply, said one analyst, James Bill, the US "views Iran through spectacles manufactured in Israel". For Mr Bush, the weapons of mass destruction-cum-missile peril is regaining ground on that of the post-September 11 terrorist one. And in that department Iran clearly outweighs President Saddam.

It has long been a built-in, unquestioned US assumption that Israel has a right to preserve its nuclear monopoly and to pre-empt any regional power's efforts to challenge it. This is a unique indulgence by a superpower of its favourite protege.

Yet Israel often hints that the US is not indulgent enough. And a touch of blackmail about what might happen if Israel does not get its way is apt to come with the hint. Thus a leading columnist, Nahum Barnea, wrote in Yediot Aharanot that on a visit to Washington this month Mr Ben-Elizier will try to persuade the administration that, Iran being "the real strategic threat", they must "deal with it diplomatically or militarily, or both. If they don't, Israel will have to do it alone."

[The Guardian Weekly 7-2-2002