The OIES's Stern says the Ukrainian pipeline network is such that it is impossible for Russia to selectively cut off Ukraine while allowing gas to flow further west to Europe.
"It's not possible to totally shut off pipelines because there are no pipelines through Ukraine that are dedicated to Europe," Stern says. "All of them serve Ukrainian customers as well as European customers and that's why it's absolutely impossible for the Russians to be sure that gas isn't being taken by Ukrainian customers which is destined for Europeans."
The Ukraine dispute, as long as it remains unresolved, represents a loss of income and a political liability for Russia. With this in mind, Putin vowed to re-route gas through the Yamal Peninsula pipeline that runs through Belarus into Poland and Germany, and the Blue Stream pipeline that runs across the Black Sea from Russia to Turkey.
Stern argues that neither represents a long-term solution to the current shortage.
Ukrainian pipelines carry some 120 billion cubic meters (bcm) of gas to Europe annually. The Yamal-Europe pipeline has a maximum capacity of 33 bcm and Blue Stream is expected to reach it maximum output of 16 bcm in 2010. So together the two pipelines cannot make up the difference of even half the gas Europe has contracted to receive.
Some countries are likely to be particularly hard hit by the suspension of supplies via Ukraine.
"I think particularly countries like Bulgaria and Greece are quite vulnerable," Stern says. "The Greeks have an LNG [liquefied natural gas] terminal, and they can perhaps bring a couple of extra cargos to that to make up for Russian supplies, but I personally think that those are the most problematic countries -- Bulgaria, Greece, Croatia, the Balkan countries, which are not big users of gas but are going to find it difficult to find supplies from elsewhere."
Countries such as Bulgaria and Macedonia do not have access to any other pipelines, save those running through Ukraine. It is no surprise then that Bulgarian Economy and Energy Minister Petar Dimitrov said on January 6 that Russia and Ukraine "must" quickly find a solution to their dispute.
Iran has floated the idea that it could help make up for the Russian gas shortage in Europe by shipping its own gas via Turkey, but Stern says he doubts it would make much difference in Europe even if it did happen.
"Essentially the amount of gas in the Iranian-Turkish pipeline is not that great, so even supposing the Iranians had the gas to do it -- which in the past, in the winter, they haven't -- I think it might help the Turkish situation," Stern says, "but I have my doubts whether there would be enough capacity to make a difference in southeastern Europe."
Factbox: Russian Gas Export Pipelines, Projects
A factbox on how gas gets to Europe from Russia and some of the new pipeline projects aimed at bringing more Russian gas to Europe and diversifying supplies. More