http://www.theguardian.com/world/2014/mar/03/europes-gas-supply-ukraine-crisis-russsia-pipelines
Is Europe's gas supply threatened by the Ukraine crisis?
Russia supplies around 30% of Europe's gas through pipelines in Ukraine – should we be worried?
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Europe accounts for around a third of Gazprom's total gas sales, and around half of Russia's total budget revenue comes from oil and gas. Moscow needs that source of revenue, and whatever Vladimir Putin's geo-political ambitions, most energy analysts seem to agree he will think twice about jeopardising it. Short of an actual war, the consensus appears to be, Europe's gas supplies are unlikely to be seriously threatened.