After the annexation of Crimea, every EU country that was either associated within the Warsaw Pact or part of the Soviet Union became a founding member of the Bucharest Nine (B9) initiative to discuss defence concerns in yearly summits. In those countries, now increasingly referred to as ‘Europe’s eastern flank’, allied military presence increased sevenfold to 300,000 units just four months into the Russian invasion. Their unyielding defence intent, stated during NATO’s summit in Vilnius, is reflected in B9’s growing military spending, which is bound to shape NATO’s most prominent defence transformation and modernisation effort since the Cold War.