The unanimous March 24 vote by the United Nations Security Council to impose stricter sanctions on Iran is the latest step in the Bush administration’s campaign to isolate the regime in Tehran and prepare the conditions for a possible military attack. The resolution came one day after Iranian Revolutionary Guard naval forces seized 15 British Navy personnel in the Persian Gulf, setting off a diplomatic confrontation between Iran and the UK.

The resolution, the second to impose sanctions in the past three months, imposes new financial penalties as punishment for Iran’s refusal to suspend its uranium-enrichment programme. It targets 15 individuals and 13 organisations, including Iran’s central bank. For the first time, it imposes sanctions on the elite Revolutionary Guard Corps and a subordinate military unit, the Quds Force, which have no relationship to the country’s nuclear programmes.

The targeting of the Revolutionary Guard, whom the US and Britain accuse of arming Hezbollah in Lebanon, Hamas in the Palestinian Authority and anti-occupation Shia militia in Iraq, combined with a ban on Iranian weapons exports, gives the United States a new legal pretext for subversion and military action against Iran.

In recent months, the Bush administration has charged Iran with arming anti-US militia, and implied that the American military has a right to attack Iran in order to defend US troops in Iraq. Washington will undoubtedly now claim that Iran is continuing to arm Iraqi militia and cite the new resolution to give it the cover of UN authority for intensified military preparations against Tehran.

“Is this aimed at preventing Iran from obtaining nuclear weapons,” asked Jean du Preez, director of the international organisations and non-proliferation programme at the Monterey Institute of International Studies, “or is this regime change in another form?”

Once again, Russia, China and the other members of the Security Council lined up behind Washington. China and Russia were opposed to tougher travel restrictions on Iranian officials and an embargo on the sale of conventional arms to Iran, but refused to challenge the essential thrust of US efforts. Russia has applied its own pressure on Iran by holding back fuel for Iran’s nearly completed nuclear power reactor at Bushehr.

Discussions on a series of amendments proposed by three of the Security Council’s non-permanent members, South Africa, Indonesia and Qatar, saw the US and Britain face down all significant changes, including South Africa’s proposal for a 90-day moratorium on all sanctions to allow for negotiations. Having expressed their concerns over the final language of the resolution, the three countries dutifully voted for it.

The New York Times quoted R. Nicholas Burns, under secretary of state for political affairs, stating, “We are trying to force a change in the actions and behaviour of the Iranian government. And so the sanctions are immediately focused on the nuclear weapons research programme, but we also are trying to limit the ability of Iran to be a disruptive and violent factor in Middle East politics.”

The pressure can be stepped up further in 60 days’ time, when the International Atomic Energy Agency is due to report back on whether Iran has suspended its uranium-enrichment programme.

There is, however, one element of the resolution’s provisions that does not go as far as the US would wish. The resolution invokes Chapter 7, Article 41 of the United Nations charter. Whereas this renders the resolution’s provisions mandatory, it does not sanction military action.

This makes all the more significant the events leading up to the confrontation between the Royal Navy and Iran in the Gulf. Though it appears that Britain is presently approaching the issue with a degree of caution, and the matter was not raised directly at the Security Council meeting, the detention of 15 Royal Navy personnel could still be used as a pretext for future military action.

The exact circumstances leading up to the incident are hotly contested. Britain, backed by the US and the European Union, claims that the eight sailors and seven Royal Marines attached to the frigate HMS Cornwall were seized in Iraqi waters by Iranian forces while aboard a dhow searching for contraband and weapons. London asserts that Iranian boats drew alongside and took the British personnel at gunpoint into Iranian waters at 10:30 a.m. local time.

But Iran insists that the confrontation was in Iranian waters and that there have been repeated incursions by British vessels into its territory. The Fars news agency said the British personnel had been taken to Tehran for questioning for “failing to respect international frontiers and for illegally entering Iranian territorial waters.”

The Iranian military has since claimed that its interrogators obtained confessions from the 14 men and 1 woman that they had strayed illegally into Iranian territorial waters.

The Iraqi military commander in charge of territorial waters issued a statement that tends to confirm the Iranian case. Brigadier-General Hakim Jassim in Basra said, “We were informed by Iraqi fishermen...that there were British gunboats in an area that is out of Iraqi control. We don’t know why they were there.”

The sailors were seized in the narrow Shatt al-Arab waterway, the confluence of the Tigris and Euphrates Rivers that forms the southern border between Iraq and Iran. The precise boundary in the waterway between the two countries has long been a matter of dispute.

In 2004, eight British military personnel were captured by Iran’s Islamic Revolutionary Guard Corps in the Shatt al-Arab. Tehran insisted at that time that the three boats intercepted were in Iranian waters, and Britain’s denials were half-hearted, containing descriptions of “appalling weather” and a “confused situation.”

Fundamentally, the incident cannot be understood outside of the escalation of political hostilities and military threats by Washington and London against Tehran. There is some speculation that the Iranians may have seized the British in retaliation for the detention by US troops in Iraq of five Iranians alleged to be Revolutionary Guards.

Relations between Iran, the US and Britain are so tense that even a relatively small dispute could spark a wider confrontation. Washington and London have been building up their naval presence in the Gulf for months, claiming that this is necessary to prevent Iranian efforts to arm the insurgency in Iraq.

The US presently has two aircraft carrier battle groups stationed in the Gulf, and Britain has committed major military resources to the US-led effort. On February 26, Britain’s senior naval officer in the Persian Gulf and deputy commander of coalition maritime operations for US Central Command, Commodore Keith Winstanley, reported that Royal Navy deployments in the region have doubled since October. In an interview with the Daily Telegraph, he made clear that this was intended at the very least as a threat to Iran. “Most of these ships are here on training missions,” he said, “but there is no doubt that we could use the war-fighting capabilities they possess.”

The British vessels sent to the Gulf include HMS Cornwall, two minesweepers, HMS Ramsey and HMS Blythe, and a vessel from the Royal Fleet Auxiliary. Winstanley referred to the area of operations as a “battle space.”

The incident in the Gulf coincided with fresh accusations by Lt. Col. Maciejewski, the commanding officer at the UK base at Basra Palace, that insurgents in southern Iraq are being funded and armed by Iran. In an interview with BBC Radio 4’s Today programme, he said he had no “smoking gun” to back up his claims, but then claimed that “all the circumstantial evidence points to Iranian involvement in the bombings here in Basra.”

Assertions that Iran is on the brink of acquiring nuclear weapons capability may have so far played the central role in the efforts of the Bush administration to justify a possible military strike on Tehran. But with permanent Security Council members Russia, China and France opposed to such a move, together with its non-permanent members, a military incident that could be portrayed as proof of Iranian hostilities against coalition forces would provide a convenient excuse for war.

This possibility was publicly raised last month by Zbigniew Brzezinski, the national security adviser in the Carter administration. Testifying before the Senate Foreign Relations Committee, he set out what he described as a “plausible scenario for a military collision with Iran” that could be used by the Bush administration.

This might involve, he suggested, “some provocation in Iraq or a terrorist act in the US blamed on Iran, culminating in a ‘defensive’ US military action against Iran that plunges a lonely America into a spreading and deepening quagmire eventually ranging across Iraq, Iran, Afghanistan and Pakistan” (emphasis added).

Publicly, Prime Minister Tony Blair has declared that there are no US plans for military action against Iran, but he has also refused repeatedly to rule out the possible use of force. As long ago as April 2006, the Telegraph reported secret talks between the Blair government and defence chiefs over the “consequences of an attack on Iran.”

The newspaper continued, “It is believed that an American-led attack, designed to destroy Iran’s ability to develop a nuclear bomb, is ‘inevitable’ if Teheran’s leaders fail to comply with United Nations demands to freeze their uranium enrichment programme.”