Britain has accused Iran of direct complicity in the killing of British soldiers in Iraq through the supply of explosives to insurgents.
The accusation is certain to have major international repercussions at a time when the United States in locked in a highly charged confrontation with Tehran over its nuclear policy.
Diplomats and international observers warned that the British claims will strengthen hawks in the Bush administration advocating punitive action against Tehran.
The British military have suspected an Iranian connection in the deaths since May of eight soldiers in and around Basra. But yesterday, for the first time, figures close to the Iranian government have been linked to attacks on British troops in Iraq.
It is also the strongest accusation against a neighbouring state over the deaths of coalition soldiers. Even Syria, excoriated by Washington for allowing cross-border infiltration by insurgents, has not been accused in similar fashion.
A senior British official claimed yesterday that the explosives were sent to Iraq by Iran's Revolutionary Guard and at least a partial motive was Iranian resentment at being "bullied" by the West over its nuclear development programme.
"It would be entirely natural that they would want to send a message, 'Don't mess with us'. This would not be outside the policy parameters of Tehran," he said. "I think the Iranians woke up one day and said 'the boys in the south [of Iraq] could use this."
The sudden increase in British casualties has been blamed on a new and sophisticated type of armour-piercing infra-red weapon used by Shia groups in the south. According to yesterday's account, the technology for the "explosively shaped projectile" - which circumvented the British military's counter measures - was developed by the Hizbollah group in Lebanon which has strong links with the Iranian Revolutionary Guard. "We think it has come from Lebanese Hizbollah via Iran," said the official.
The attacks, according to British officials, were carried out by members of a breakaway faction of the radical Shia cleric Muqtada al-Sadr's Mehdi Army. Its leader, Sheikh Ahmed al-Fartusi, has been arrested by British forces.
British officials say they were working with their Iranian counterparts towards an agreement to halt the smuggling of the explosives, but this was abandoned after the election of the hardline Iranian President Mahmoud Ahmadinejad. The officials acknowledged, however, that Tehran had consistently denied any involvement in the attacks, and observers warned against jumping to the conclusion that this was deliberate Iranian government policy. They pointed out that the long and porous border between Iran and Iraq made policing extremely difficult.
But British officials accused Tehran of actively trying to "destabilise" Iraq, claiming Shia Iran was not only helping Shia groups in Iraq, but also Sunni insurgents. "There is some evidence that the Iranians are in contact with Sunni groups," said the senior official. "I don't think it is for a benign purpose. It is part and parcel of Iranian efforts to destabilise Iraq. If part of the aim was to tie down the coalition in Iraq, it would be entirely consistent with supporting these groups."
Two months ago Britain formally protested to Iran over alleged interference in Iraqi affairs and attacks on coalition troops. At the time it cited the "smuggling" of arms and explosives across the border without making any direct allegations against the Iranian government apparatus. The British protest was followed up by an aggressive statement from the US Defence Secretary, Donald Rumsfeld, who made the veiled threat that "ultimately it will be a problem for Iran".
The British position towards Iran's nuclear programme has also noticeably hardened, with the Government seeking to refer Tehran to the United Nations Security Council where it may face sanctions. Iran, in turn, has rejected proposals from Britain, France and Germany that it abandon fuel cycle technology in return for incentives, and announced that it was scrapping an agreement with the three countries to halt uranium conversion.Reuse content