Will the success of US-Russian cooperation in reaching a major agreement on Iran’s nuclear program create a new opportunity — and new momentum — for a political solution to Syria’s seemingly unending civil war? Both Washington and Moscow appear to be leaving the door open. But walking through it will not be easy.

The Iran deal has produced a level of mutual congratulations in the US-Russia relationship that, however mild, has not existed for some time. According to the White House, President Barack Obama “thanked President [Vladimir] Putin for Russia’s important role in achieving this milestone” during a July 15 telephone conversation. Two days later, the Kremlin announced that Putin and members of Russia’s Security Council — including Russia’s top military, intelligence and security officials, who are generally not Washington’s best friends in Moscow — “noted again that the leading role and constructive position taken by the United States played a big part in making it possible to finalize the agreements” during a meeting chaired by Putin. This ritualistic exchange of praise was quite different in tone from many other recent statements from the two governments.

At the same time, each side has drawn particular attention to the related problems of Syria and the Islamic State (IS) in reporting on their dialogue and assessing the future. In his news conference on the Iran agreement, Obama said, “We’re not going to solve the problems in Syria unless there’s buy-in from the Russians, the Iranians, the Turks, our Gulf partners,” adding, “There’s going to have to be agreement among the major powers that are interested in Syria that this is not going to be won on the battlefield.” Russian Foreign Minister Sergey Lavrov expressed optimism that “the largely artificial obstacles to forming a broad coalition in the fight against the Islamic State and other terrorist groups are being removed.”

These statements, and renewed modest goodwill between Washington and Moscow, do seem to provide another chance to work together on Syria. That said, achieving results — rather than simply “opening a dialogue” — will be quite challenging.