Good thing it's been a mild winter in Europe, because supplies of Russian oil to Poland, Ukraine, and Germany have just been put in a squeeze.
This all began late last year, when Russia decided to double the price of the natural gas it sells to Belarus. This came as rather a shock to Belarus, heretofore Russia's bosom buddy, but Russian President Vladimir Putin is — depending on your point of view — "using energy as a weapon" to keep former Soviet states in the Russian orbit, or ending Soviet-legacy subsidies that kept energy prices to former Soviet states super-low. Or both.
By year's end Belarus agreed to go along…but then it slapped a user fee on the Russians for the right to send oil through Belarus pipelines, which the Russians are refusing to pay. So, as a new week begins the flow of the oil through Belarus to points west and south is getting squeezed, and there's no telling how the dispute will play out.