Europeans cannot decide what they fear more: relying too much on Russian gas or not getting enough of it. We worry about the Kremlin's political machinations and Gazprom's underinvestment in equal measure. But restricting Russian investment in Europe will not solve either problem.

More than a third of European Union gas imports already come from Russia. Of course, this dependence is not one-sided. For Russia, these sales are a significant source of foreign exchange. All big Russian gas pipelines go to the EU. It will take years to build the pipes and liquid gas terminals to ship Russian gas eastwards to China or the US.