With the price of oil close to a new high for 2009, even if it slipped a fraction yesterday, it’s no surprise that Iran is confident enough to try to bend the terms of the supposed new deal to send its most sensitive nuclear material to Russia and France. Of course, to claim a simple motive for the actions of the many-headed Iranian regime would be wrong. But in the seven-year wrangle over its nuclear work, there has been an extraordinary correlation between the regime’s taste for antagonism and the level of oil futures.

Today Ayatollah Ali Khamenei, the Supreme Leader, and President Ahmadinejad will urge Iranians to celebrate the 30th anniversary of the storming of the US Embassy. The leaders cannot be sanguine about the ability of the opposition to rally the simmering public fury about the summer’s “stolen” presidential election. But oil cash brings them a bit more confidence; about their ability to withstand foreign sanctions, if more are imposed, and to buy peace with subsidies at home.

They warned that anti-regime protests will not be tolerated, and the head of Tehran’s security forces, General Ali Reza Alipour, said that police would use all their “power and capacity to confront any demonstrators”. But those threats were packaged with prominent cash offers. Yesterday Ahmadinejad reversed a scheme to cut subsidies on food and fuel. “We will take back the bill,” he said, overriding some conservative parliamentarians who have argued that the Government needs the funds.

The leaders’ ability to continue to crush that opposition may prove limited, for all Khamenei’s shower of insults yesterday, calling “naive” those who pinned hopes of change on reformists. But the leaders’ confidence in rebuffing pressure from other governments over the nuclear work, which depends on their sense of containing rebellion at home, has clearly recovered from the low point at the United Nations General Assembly in mid-September. Then, they were embarrassed by the US’s revelation of covert nuclear work at Qom, disconcerted by Russia’s apparent support for a tough US line and were defensive about widespread censure of the election. They had no clear tactic for responding to President Obama’s offer of direct talks, other than the now-routine fusillade of direct insults.

Yet in six weeks, Iran has worked with some success to get Qom scooped up into the framework of regular UN inspections, and has persuaded Russia to drop its apparent support for the US’s tough position. Now it wants to rewrite the deal the US thought it had secured, under which it would ship out its most controversial nuclear material to Russia and France for processing. The deal would relieve much of the anxiety of other governments about Iran’s ability to divert the material to weapons, and might buy a year’s time in the programme’s progress, one US official said.

Hillary Clinton, the Secretary of State, speaking from Marrakesh, said that the deal had been agreed in principle and the US would not change the terms. But its enforceability depends on Russia, and the cool tone of her recent Moscow meetings is not encouraging.

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