America's capital is once again abuzz with talk of war, not only of the latest "strategy for victory" in Iraq, but now also of military action against Iran. The harder it becomes to discern any rationality in the Bush administration's actions, the louder the rumour mill grinds.

Will Bush order an air and special forces attack on Iran?

Ever since Bush's state of the union address at the end of January, hardly a day has passed without something happening in connection with Iran or without the Bush administration's ratcheting up its rhetoric. Clearly, the US is also pressing ahead with preparations for an air strike. (A more extensive military commitment is scarcely possible, given how overstretched US ground forces already are.)

Indeed, the confrontation with the Iranians in Iraq is visibly intensifying, and it may be gathering strength elsewhere as well. A bomb directed at the Iranian revolutionary guard recently exploded on Iran's border with Afghanistan. And there are, of course, new attempts by the United States to drum up "evidence" of an Iranian threat that may justify an attack.

Is this all a bluff? The world could perhaps calmly wait for an answer, but for the fact that the progress of Iran's nuclear programme and the approaching end of President Bush's term might create an incalculable dynamic of its own.

As with Iraq, America's strength may be enough to start a war, but not to win it. But the consequences of a military adventure in Iran would far surpass those of the war in Iraq. Doing things by halves yet again in the Middle East would be the worst of all possible options - bad for the region and bad for its neighbours. The first among the neighbours affected would be Europe.

So how has Europe, with its vital security interests at stake, responded to these developments? The British prime minister, Tony Blair, has already adapted to the US administration's new confrontational rhetoric. The French president, Jacques Chirac, unguardedly speculated that an Iran with one or two nuclear bombs might not pose a serious a threat, given the possibility of nuclear retaliation - his musings so startled French officials that they quickly jumped in to correct the president's comments.

The German chancellor, Angela Merkel, gives speeches at security conferences that find favour in America, but otherwise Germany prefers to stay in the background.

Across Europe, risk avoidance seems to be the order of the day, even at the expense of the common interest and Nato solidarity. The German navy is defending the Lebanese coast against Hizbollah, while other European nations bear the brunt of policing Lebanon on the ground. In Afghanistan, Germany, with its strong military presence in the north, has been turning a deaf ear to calls for help from the Canadian allies fighting a revived Taleban in the south. Germany now wants to send some Tornado jets for reconnaissance purposes - better than nothing, but not by much.

In terms of security policy, Europe is stagnating, if not regressing, at the very moment when unity is needed more then ever. The Big Three of Europe - and Germany, as the current EU president in particular - must find a way to act together in strategic security matters. If they don't, Europe will largely cease to matter when the going gets rough. And the going is now getting quite rough in Iran and the Persian Gulf.

Should Iran be attacked this year, the consequences will be borne first and foremost by the region, but also by Europe as the Middle East's immediate western neighbour - and they will be felt for a long time to come. Indeed, Europe will have to share the costs if Iran prevails and becomes a nuclear power. So there is much at stake for the old continent.

To be precise, two overriding EU security interests are at stake: avoiding a war with Iran and preventing Iran from becoming a nuclear power. These two apparently contradictory interests can be reconciled and translated into a common strategy by adopting a three-pronged approach based on efficient isolation, effective containment, and direct negotiations.

The Europeans - led by Merkel, Blair, and Chirac - should agree to assure the US that Europe is ready to pay a high, perhaps very high, economic price by taking decisive action to intensify the sanctions against Iran. But they should offer this only on two strict preconditions: that the military option be taken off the table, and that all parties involved - including the US - enter into direct negotiations with Iran.

The policy of isolation coupled with direct negotiations would be strengthened further by a common strategy toward Syria, aimed not at "regime change," but at "coalition change" - that is, drawing Syria away from its close alliance with Iran.

It was both right and important that the EU council of foreign ministers agreed on sanctions against Iran. Faced with the threat of financial sanctions, Iran's political elite is increasingly realising the price of its confrontational course. It is imperative to further this process in a resolute manner, while at the same time rejecting military adventurism.

It is up to Europe to prevent the two worst developments in Iran - war and nuclear armament - by acting jointly and with determination. Vital European and transatlantic interests are at stake. It is thus Europe's responsibility - and especially Germany's, as the current EU president - to act now.

Joschka Fischer, a leader of the Green Party for nearly 20 years, was Germany's foreign minister and vice chancellor from 1998 to 2005. He is now a visiting professor at Princeton University's Woodrow Wilson School.

Project Syndicate, 2007.

Joschka Fischer

Princeton, New Jersey