Timothy Snyder is Professor of History at Yale. His latest book, Bloodlands: Europe Between Hitler and Stalin, was published last year. His new book with Tony Judt, Thinking the Twentieth Century, will be published in February. (November 2011)

Few countries have a better case for sovereign government and the rule of law than Ukraine. Even today you can take a short ride from the capital Kiev, as I did a couple of weeks ago, and speak to villagers who still remember the catastrophe of 1933, when Ukraine was a republic of the Soviet Union, and more than three million of its inhabitants starved when Stalin decided to blame the Ukrainian people for the failures of his own policy of collective agriculture. Intermingled with these recollections are memories of the German invasion only eight years later, which brought a second starvation campaign alongside the better known crimes of the Holocaust. In a world where food was a scarce resource, both Stalin and Hitler were obsessed with the Ukrainian “breadbasket,” and millions of Ukrainians died as a result.

About eight decades after the famine of 1933, and two decades after the end of the USSR, the strategic resource that binds Ukraine to both Moscow and Berlin is not food but natural gas. Ukraine’s major source of geopolitical significance is the Soviet-era pipelines that transport natural gas from Siberia to Europe. The terms of the gas trade are a major issue in Russian-Ukrainian relations, and the possibilities for profit a magnet for Ukraine’s post-Soviet oligarchs. Julia Tymoshenko, the best-known Ukrainian politician, made her fortune in the gas trade before making her name by cleaning out some of its corruption. As prime minister after the democratic Orange Revolution, she signed a deal with the Kremlin in early 2009 that governs the price and flow of gas from Russia. Now, in a case overseen by her arch-rival, current president Viktor Yanukovych, Tymoshenko has been convicted of “abuse of power” for making this deal—a judgment that has landed her seven years in prison....