Expanding the Bucharest 9 is increasingly presented as a possible answer to NATO’s evolving security needs on the Eastern Flank, especially after the growing political alignment between B9 members and the Nordic countries. This analysis argues that a broader format does not automatically produce more security. Real deterrence still depends on capabilities, planning, military mobility, infrastructure, air defence, interoperability and defence industrial capacity, not on the diplomatic geometry of a political platform. For Romania, the central strategic task remains clear: keeping the Black Sea high on the Allied agenda and preventing the priorities of NATO’s south-eastern flank from being diluted inside a wider regional framework. The article also examines a more sensitive dimension of the debate: whether a broader B9 could gain additional relevance if Europe is forced to prepare for a gradual reduction in American strategic engagement. Diplomatic enlargement may have political value, but it should not be confused with an automatic strengthening of defence.