The Iranians are sensitive people. From time to time, however, they do something dumb. The seizure of 15 British sailors and Royal Marines was one such example. Parading them on television and requiring them to mouth unconvincing apologies was another.

These events have not happened by accident. For some time the more radical elements in the Iranian government have been trying to find a wayof retaliating against the growing pressure from the UN in general and the US in particular. They have been surprised and disturbed that as a result of their nuclear programme, Washington has now achieved a second unanimous Security Council resolution ratcheting up sanctions against Iran.

The Iranians, of course, are indifferent as to whether the British were in Iranian or Iraqi waters. The British were taken for two specific reasons. First, the Iranians want to demonstrate that they will not be passive while UN pressure is increased on them. They can, and will, retaliate through their close links with the Shia militia in Iraq and Hizbollah in Lebanon. They can disrupt normal traffic in what used to be called the Persian Gulf. But they have a second objective. Some weeks ago the Americans arrested Iranians in the north of Iraq. They are still detained, accused of helping foment strife against the coalition forces. Tehran may be hoping to trade the British personnel for their citizens.

There is little doubt the British will, eventually, be released but it could now take weeks or months. The Americans have, quite rightly, rejected any deal. That should also be the policy of the British. Any deal would create a precedent that would encourage further kidnapping not just by Iranians but by friends and allies in the region.

But is there any other approach that will secure their freedom? I salute Margaret Beckett and the Foreign Office who have not only demanded that the British be freed, but also secured impressive diplomatic support from many governments and have taken the issue to the UN. Most welcome has been the strong pressure from the Iraqi government and from Turkey. But this will not be enough in the short term.

Iranians will have expected the protests. They are used to playing a long game. At the beginning of the Islamic Republic in 1979, US embassy hostages were held for months. The failure to secure their release helped ensure the defeat of Jimmy Carter, then running for a second term. The mood in Tehran is not so radical now. Ahmadinejad may go in for radical rhetoric but the Supreme Leader, Ayatollah Ali Khamenei, and his advisors will be more calculating. They will not be impressed by Western speeches. They will be by Western action.

The challenge the British government faces is to find a means of putting real pressure on Iran that would hurt the regime without escalating the crisis and pushing the Iranians into a humiliating climb-down.

In an ideal world quick action by the UN Security Council would have been the way forward. But the Russians and Chinese insisted on a watered-down statement that neither condemned the Iranian action nor called for the immediate release of the prisoners. There was, however, one other approach. The members of the EU aspire to having a common foreign policy. What better issue could there be on which our French, German and Italian allies and partners could show solidarity with the UK and demonstrate the benefits of joint action? The best means of pressure would have been the export credit guarantees that are given to assist trade between Iran and western Europe. These, together with banking and other financial facilities, are the soft underbelly of the Iranians and their withdrawal could do significant damage to Iran’s already weak economy. Such measures have already been canvassed by the Americans in respect of Iran’s nuclear defiance.

The firm statement made by EU foreign ministers calling for the ‘immediate and unconditional’ release is welcome. But the apparent lack of any agreement over economic pressure has two serious consequences. First, it makes it very unlikely that Britain will be able to secure the release of the service personnel in the short term. Second, it is now almost inevitable that Iran will try to impose conditions from the international community and, in particular, the US, on their ultimate release.

This lack of agreement shows how hollow are the aspirations to a common European foreign policy. France and Germany should be ashamed at their refusal to assist their European partner in a humanitarian cause of this kind. If there had been a political will, there could already have been agreement.

All this would have been even more probable if a European threat had been conveyed privately, letting Iran back down without too much loss of face. It will be pressure and not rhetoric that will impress the Iranian regime. If the EU is not prepared to help, there will now be a pause. The ball will now be in the Iranian court. — The Guardian