Which country to the west of Ukraine is miportant to Russia and why?

Until Russia's invasion of Ukraine in 2014, the two countries maintained relations that at times were testy, but manageable. But following Moscow's annexation of Crimea, writes Steven Pifer, attitudes within Ukraine toward Russia have hardened to a consider­able degree, and the appeal of Western institutions such as the European Union and NATO has grown. This piece originally appeared in The Ambassadors Review, the foreign affairs journal of the Council of American Ambassadors.