Mr. Putin, in the first visit by a Russian leader to Iran since Josef Stalin met with President Roosevelt and Prime Minister Churchill in Tehran in 1943, has cast himself as the go-between, siding with America until now in an effort to bring Iran into line with the demands of the U.N. Security Council.
In his final months as president, Mr. Putin is seeking to pull off a diplomatic coup in Tehran that would settle the Caspian dispute in Iran's favor in exchange for Iran being more open to the world about its nuclear plants.

Mr. Putin appears to be hoping that a pacified Iran might allow NATO to postpone or even abandon its plan to site missile shield technology in European states bordering Russia, ostensibly to intercept an Iranian missile attack on Europe, an issue that has angered him.
Iran is relying on the Russian leader, in concert with the Chinese communist leadership, to prevent the adoption of sterner American proposals.