"U.S. policymakers have supported European Union (EU) efforts to reduce reliance on Russian natural gas, especially after Moscow temporarily halted exports via Ukraine in 2009 and 2006. Although European governments have generally supported the goal of diversification, they have been challenged to reduce Europe's dependence on Russian natural gas, which accounted for 37% of European imports in 2017, up 5% from the previous year. Analysts cite various impediments to reducing European reliance on Russian gas, including divergent perceptions within Europe on the reliability of Russian supplies. Many have criticized Germany, Russia's largest natural gas customer, for seeking to expand the Nord Stream pipeline system. Others suggest an expansion of Nord Stream would not necessarily lead to a rise in Russian gas imports by Europe, if Gazprom uses the new capacity to substitute for gas transit through Ukraine."
CRS In Focus, IF10943