Adam

“Natural gas, even more than oil, had become Russia’s most powerful tool in foreign policy. Oil trades freely, sloshing through the world’s economy; gas requires fixed pipelines, linking the nations of Europe to Russia. The network of pipelines, dating to the Soviet era, gave Russia clout and, with rising energy prices, the prospect of the wealth that Putin nearly a decade before had argued in his dissertation was the core of the state’s power. Ukraine,”
― Steven Lee Myers, The New Tsar: The Rise and Reign of Vladimir Putin