During the war, on 12 September 1944, the European Advisory Commission, comprising delegates from the USSR, the United States and the United Kingdom, reached an agreement (to which France later acceded) specifying that, after the war Germany was to be divided into four occupation zones. This agreement stipulated that Berlin would be under joint occupation, without separating it into a fifth zone.
When Russia stopped gas supplies at the beginning of the year, Bulgaria turned out to be not an energy but an isolated centre in the Balkans, says Georgi Angelov, senior economist with the Open Society Institute, speaking about the consequences of the crisis.
"For several years now, our country has been perceived as Russia's Trojan horse in the EU – energy policy included," he says. "Bulgaria does not support the idea of greater integration and liberalisation of the energy sector that the EU is trying to pursue."