Europe is not the only region affected by Britain's vote to leave the European Union. The decision will also have significant effects on Russia, especially where sanctions are concerned. As the Continent focuses on mitigating and managing the fallout from the Brexit vote, it probably will have fewer resources to devote to problems beyond the European Union, namely those in Ukraine, Syria and Nagorno-Karabakh -- all areas where Russia plays a major role. The European Union is also likely, at least in the immediate term, to have less interest in advancing its political and economic integration projects in the former Soviet periphery, such as the Eastern Partnership program....