Leading article: A welcome change of tack by Washington

The surest reason for believing that America really has reversed its policy on Iran, to the pursuit of face-to-face negotiations and the establishment of a US office in Tehran, is the outrage it has caused among hardliners in Washington. It is, according to John Bolton, George Bush's former ambassador to the UN and a noted hawk where Iran is concerned, a "sell-out" and an abandonment of a policy of forcing Iran to stop its nuclear programme through military threats and trade sanctions.

Washington's change of approach towards the prime member of Mr Bush's original "axis of evil" is no such thing, of course. What it amounts to is a sensible move from war-war to jaw-jaw at a time when talks between Iran and the European UN members over Iran's nuclear ambitions appear to be making some headway. True, the White House has to date always said it would refuse to sit down in negotiation with Iran until the latter ceased its uranium enrichment activities (although it has sat down with Iranian representatives in talks about Iraq). It is true, too, that the White House has, until now, believed that only the threat of military action would pressure Iran to halt its nuclear programme.

But the mood has changed, in Tehran as much as Washington. In the first place, the threat of war has proved largely counter-productive, playing into the rhetorical hands of Iran's firebrand President, Mahmoud Ahmadinejad. The more the option has been discussed, the more the sheer practical problems of carrying out an effective strike that would disable Iran's plants without producing a conflagration, have loomed large, as a steady stream of generals has declared in public.

The threat of further sanctions, on the other hand, does seem to have produced a more positive response from Tehran. The precise intentions of Iran's government are always hard to determine, given the opaque nature of its leadership. But there have been signs that, beset by popular unrest at rising prices and besieged by sanctions, the supreme ruler Ayatollah Khamenei desires to step back from outright confrontation. Iran should be enjoying an economic renaissance with the high price of oil, but it isn't and its public wants to know why.

It is fruitless to argue about which side is blinking first. Neither has done more than express a willingess to talk. But we have two forces coming together. On one side is a US President who, in his final year, is moving back to the paths of traditional diplomacy, not just with Iran, but North Korea and the Middle East. On the other side we have an Iranian President who is coming under restraint from Iran's old establishment. It doesn't make a summer but it does make a fluttering dove.