In its negotiations with the United States on any number of geopolitical issues, Russia has become accustomed to playing its "Iran card." But after the West's historic nuclear agreement with Iran, some experts are suggesting Russia will have less of a hand to play in negotiations on various topics, not just with Washington but with other world leaders. Ed Morse, head of commodities research at Citigroup, told CNBC that as a result of the agreement, Russian's position with regard to its oil exports to Europe is particularly vulnerable. Read More'More pain coming' to oil sector: Energy investor "Oil companies in Europe, especially the Mediterranean market, are eager to strike upstream exploration and production contracts in Iran and will want to show that they are eager to resume business ties there," Morse said. "The best short-term way to do that is to buy more Iranian crude, and the main victims of that will be Russia along with Iraq."

President of the Russian Federation Vladimir Putin. Getty Images

Even before the deal was signed, Donald Jensen, resident fellow at the Center for Transatlantic Relations, wrote that Russia is likely to lose out from such a deal over the long term. Iran will now have better access to global energy markets, providing competition for Russian energy, he said.

"Even as it tries to keep good ties with Moscow, Iran will likely offset them by pursuing better ties with the West," he said.

But others say they believe Russian President Vladimir Putin when he hails the deal as a positive step for the Middle East, which he has done publicly.

