I believe that there is a certain turmoil in the relationship between the Russians and the Americans. To me it seems as a conflict over turf. Syria is the turf of the Russian led Shia side, and Americans and Saudis bombing there seems to be an affront.
Well, to put things in perspective, we could draw a parallel to Ukraine. Here things are the same, just with different actors. Russia sees this as a home/domestic issue, and see Americans as making conflict. In Syria, the Americans need to defend their own interests in Iraq, and needs a bit of room for that.
As I mentioned earlier. This situation therefore holds a certain room for negotiation. As Mr. Barack Obama has already signalled. In other words, he is ready, as I understand it, to loosen up sanctions, and give Russia more room of maneurability in Ukraine, if Russia gives him the same in Syria.
This of cause does not leave either Syria or Iran with any relieve over the attacks in their home turf. But there is a possibility to make amends, and have a little more room in other negotiations.
But, into equation comes two other things. One is the relationship to Israel, the other is the upcoming election in the US. The US has to make sure Israel feels a part of the negotiation regarding the descalation of arms in Iran. Obama has to have something to show in the election in the US in november.
The only way this equation can be solved, is if everybody tries to put away their immidiate fears, and tunes in for a viable solution.
G-d bless the will to make peace.