I WAS invited with a small group of journalists to a briefing today by Barack Obama on his Iran policy. The president unveiled no new policy but explained how his strategy towards the Islamic Republic had proceeded since he took office. In his telling, the administration has advanced in methodical steps towards its goal of ensuring that Iran does not acquire nuclear weapons. It has, he asserts, been a piece of "well-executed diplomacy" using "all elements of national power".

Mr Obama says the various components of his policy should not be seen in isolation. First he tried to engage Iran early and directly, not because he was naive about the regime but in order to make clear to the world that America was not the aggressor and was willing to work with Iran if it behaved reasonably. A second part of the strategy was to emphasise nuclear non-proliferation as a global good, by living up to America's own responsibilities under the Nuclear Non-Proliferation Treaty (NPT) and organising a successful NPT review conference. Element three was resetting American relations with Russia. This was a good thing in itself but was also designed with Iran policy in mind. Only by talking Russia round first was America able to persuade China to sign up for tougher new sanctions on Iran. In the end, such was Russia's commitment that the Kremlin agreed to hold back certain arms sales to Iran at a considerable cost to itself. All this culminated in the new UN Security Council sanctions on Iran, which have in turn served as a platform for other initiatives, such as sanctions imposed separately by the EU, Canada and the United States itself.

As to whether the additional pressure piled on Iran would in fact change its mind about pursuing nuclear weapons, Mr Obama said he did not want to overstate his expectations. Changing Iran's calculations would be difficult. The Iranians were surprised by how tough America had been and this had given rise to internal "rumblings". But there was a nationalist and ideological component to their quest for nuclear weapons that might ultimately override any cost-benefit analysis. That meant the United States had to keep looking at "all available options" (force?) that might be able to prevent Iran from acquiring a bomb. He was not ready to lay down any public red lines "at this point". Interestingly, he did say that it was important to set out for the Iranians a clear set of steps that America would accept as proof that the regime was not pursuing a bomb: they needed "a pathway". With hard work, America and Iran could thaw a 30-year period of antagonism—provided Iran began to act responsibly.

Mr Obama said that the United States had received no direct contacts from Iran's President Mahmoud Ahmadinejad or its supreme leader, Ayatollah Ali Khamenei, though high-level officials in Iran had investigated the possibility of re-engaging with the P5-plus-one (the permanent members of the Security Council plus Germany). America would be willing to talk bilaterally to Iran "in the context" of a P5 process that was moving forward. There should meanwhile be a "separate track" on which America could co-operate with Iran on other issues, such as Afghanistan and drugs, for example.

Senior administration officials speaking after the president's briefing were bullish about their ability to tighten the squeeze on Iran economically and diplomatically. Sanctions were making it ever harder for Iran to find foreign investors in its vital oil and gas sector. The EU had adopted tougher sanctions than anyone was expecting. It was already hard for Iran to do business in dollars, and now its ability to do business in euros was being impaired as well. For the first time Tehran's bazaaris, the commercial middle-class, had expressed their unhappiness, adding their protests to those of students and intellectuals. America had firmed up defence relations with the Arab Gulf states and taken unprecedented steps to reassure Israel about its security. Meanwhile Iranian efforts to enrich more uranium seemed to be encountering difficulties. The 3,800 first-generation centrifuges in Natanz were operating at about 60% of their capacity and were experiencing a high rate of breakages (though there are 4,000 in reserve). A planned second generation of centrifuges had not yet been installed. If Iran were to expel international inspectors and dash for a bomb, said a senior administration official, it would take it a year or more to collect enough fissile material for a single device.

What to make of all this? In the end a briefing is just a briefing, and the president of the United States is hardly going to tell a bunch of journalists that his policy to stop Iran from acquiring nuclear weapons has been anything less than dynamic and methodical. What does seem beyond dispute is that the Obama administration has succeeded in driving an unexpected wedge between Iran and Russia, a country the Iranians had long assumed would continue to offer them a degree of diplomatic protection. That is a serious achievement, as are the new international sanctions to which the Russians and therefore the Chinese have recently agreed. Whether all these elements of pressure will persuade Iran to abandon its alleged ambition to become a military nuclear power (an allegation it strenuously denies) remains to be seen. It may be telling that Mr Obama himself is playing down expectations and beginning to talk more about the other unspecified "options on the table". Then again, that could just be a bit of bluff intended to pile on even more pressure.