By Jon Leyne
BBC News, Tehran
Putin made an unspecified proposal on Iran's nuclear programme
The Iranian authorities have already declared the visit a triumph.
President Mahmoud Ahmadinejad was clearly delighted to welcome President Vladimir Putin, the first Kremlin leader on Iranian soil since 1943.
But, in public at least, Iran secured few concrete commitments from the Russian president during the meetings in Tehran on Tuesday.
"Russia and Iran are both in the same boat in fighting American unilateralism," declared Jam-e Jam newspaper confidently. "The western countries did whatever they could to stop [Mr Putin] from attending this conference."
Keyhan newspaper, which is particularly close to the Iranian leadership, said the summit meeting was a "considerable achievement for Iranian diplomacy".
It is certainly very significant that the Russian leader agreed to come to Tehran.
As Mr Putin's antipathy for the United States grows, so his support for Iran has warmed.
Only last week he declared there was no evidence Tehran was working on a nuclear bomb.
A new round of sanctions against Iran, being pressed by Washington at the United Nations, has stalled because of opposition from Russia and China.
Stalin was the last Russian leader to visit Tehran in 1943
With all that in mind, the Iranians may be disappointed they did not get a more unequivocal expression of support from Mr Putin in Tehran.
At the summit of five Caspian sea leaders, Mr Putin said: "We should not even think of making use of force in this region."
But his comments about Iran's nuclear programme were more subtle:
"Russia is the only nation which is helping in the development of [Iran's] peaceful nuclear programme," he explained.
"And in fact, as the president of Iran has already remarked, in the declaration we signed today all the Caspian Sea governments support this agreement, which is against the proliferation of nuclear weapons, but declares we all have the right to develop a peaceful nuclear programme without these restrictions."
That's a position no Western leader would disagree with.
And when Mr Putin was asked about the Bushehr nuclear reactor that Russian engineers are building on Iran's Persian Gulf coast, he was even more coy.
Would he give a promise to supply fuel for the reactor, he was asked.
"I only made promises to my mother, when I was a little boy," he joked.
Putin said the Bushehr nuclear reactor would be finished
Though he went on: "From the very beginning Russia said that it intends not only to sign a contract but finish the job. And we are not absolving ourselves of our obligations."
None of this suggests Russia is about to move into a new strategic alliance with Iran.
Indeed, before the visit began, many commentators warned that Russia should not be trusted.
"Russia fans the flames of the Cold War with America by playing the Iran card in order to get as many concessions as possible from the west to beef up its economic and political position in the world," explained E'temaad newspaper.
Hours after President Putin's departure it emerged that he had presented an unspecified proposal about Iran's nuclear programme.
According to the state news agency IRNA, the ideas were put forward in a meeting with Supreme Leader Ayatollah Ali Khamenei, the most powerful man in Iran.
No details have emerged, though one suggestion is that Mr Putin was proposing that Iran suspend uranium enrichment in return for a suspension of UN sanctions.
According to IRNA, the supreme leader told Mr Putin: "We will ponder your words and proposal."
It seems this proposal from President Putin may have been the main reason for his visit.
He came to Tehran as peacemaker, in other words, not to forge a new alliance.
And the outcome of the meeting is still very much in the balance.