By Paul Reynolds
World Affairs correspondent, BBC News website
A meeting between the American and Iranian ambassadors to Iraq in Baghdad on Monday is part of a potentially significant shift in US policy towards the recommendations of the Iraq Study Group last December.
Iran is accused of providing bomb technology used in Iraq
It was the first formal, bilateral meeting between the two countries since relations
were broken off in 1979.
The hope has to be that each side will co-operate more in a shared strategic interest of getting a stable Iraq.
The fear is that each side sees this process simply as a way of blaming the other for the ills of Iraq.
Afterwards the US Ambassador Ryan Crocker indicated that he had done what he had come to do - he had urged Iran to stop giving what the US says is military and technological help to militias fighting US and British forces.
The Iranian envoy Hassan Kazemi Qomi told Iranian television: "What was clearly and transparently said in today's
talks were the problems and faults caused by the American's
wrong performance and management in the security case."
He said the US should have handed over to an Iraqi government at once and should enable the Iraqi to have a strong security force. He also criticised the behaviour of American troops.
It remains to be seen whether there will be further meetings (Iran is apparently in favour) and whether this is the start of something significant.
US policy shift
The meeting does take its place in a pattern of US behaviour which is seeing a modification of the previous hardline position.
For example, the US backed away from the condition it once set for such a meeting.
When the Iraq Study Group recommended engaging with Iran about Iraq, President George Bush said this could not happen unless Iran first acted by "standing up for the right principles".
He put it this way: "You support the democratic elected government; you do not support sectarians and you do not support, arm or finance terrorists."
He also laid down that for a wider engagement, principally over the nuclear issue, Iran first had to suspend its enrichment of uranium.
The condition for the talks over Iraq went. While agreeing to the meeting, the US was simultaneously accusing Iran of carrying out the activities it was supposed to drop in advance.
It appears that the meeting was so important as the US tries to steady the situation in Iraq that the condition had to be put to one side. Iran can no longer be ignored.
Smaller US force
Mr Bush has also moved towards another important recommendation from the study group - the regrouping of US forces in Iraq away from direct combat.
This is what the president said last week, on 23 May: "The recommendations of Baker-Hamilton appeal to me, and that is to be embedded and to train and to guard the territorial integrity of the country and to have special forces to chase down al-Qaeda.
"But I didn't think we could get there unless we increased the troop levels to secure the
capital. And so, therefore, the decisions I made are all aimed at getting us to a different
Mr Ahmadinejad said Iran would not back down over nuclear ambitions
The US Defence Secretary Robert Gates followed this up by saying that the Pentagon was now planning for a smaller US force in Iraq.
There is still no talk of a timetable for a withdrawal.
The big issue not discussed at the meeting was the nuclear one. But it is one that
could swamp any progress towards a rapprochement.
Iran is defying the Security Council's demand that it suspends enrichment and President
Mahmoud Ahmadinejad said again on Sunday that Iran would ignore this.
"It will be in the interest of the bullying powers to accompany the Iranian nation with its peaceful nuclear programme," he said.
The US and its closest supporters - Britain, France and Germany - have rejected a suggestion from Mohamed ElBaradei, head of the International Atomic Energy Agency, that they accept a limited Iranian enrichment plan in exchange for strict supervision.
Instead, further sanctions on Iran will be discussed over the coming weeks.