Both following Putin's February 2022 invasion and the earlier 2014 annexation of Crimea, the U.S. was the first major allied nation to reinforce nervous countries in Eastern Europe, as well as by far the single biggest backer of Ukraine itself when it comes to weapons and intelligence. Over the last two decades, Washington has also occupied a valuable piece of ideological middleground within the alliance: less hawkish on the Kremlin that Eastern and Central European states, but also less prone to rapprochement and unrestricted trade in France, Germany or some other Western European member...