Despite diverging priorities among different European countries, NATO and transatlantic security cooperation remain the foundations of Europe's defense architecture. The Continent's fundamental interest is to maintain internal stability and deter external threats, primarily from Russia. However, deep-seated divisions persist over how to achieve these goals and the extent to which reliance on American security guarantees should take precedence over developing greater European strategic autonomy. The Russia-Ukraine war has underscored both the indispensability of U.S. military support and the risks of overreliance on Washington, fueling renewed European debates on defense spending, industrial capacity and military coordination. ...