Russia’s full-scale invasion of Ukraine has fundamentally altered European security, exposing the vulnerability of NATO’s eastern flank. The accession of Finland and Sweden may have strengthened the Alliance, but it also expands the maritime battlespace deep into the Baltic Sea. Meanwhile, U.S. defense planning is increasingly dominated by the Indo-Pacific and competition with China. How can Europe collectively defend the Nordic-Baltic region—even in a scenario of constrained U.S. support? To answer this question, the paper turns to strategic theory and maritime history.

Command and control (C2) is fundamental to military practice, yet no one can clearly define what it is. That is not a minor flaw. It reflects a deeper uncertainty about what command itself means. This problem is approached by examining competing definitions and deeper conceptions of C2, the persistent tension between centralisation and decentralisation, and how these dynamics are reflected in doctrine and historical cases. At its core, C2 reflects a tension between the desire to control and the need to act. Developments in communications technology have not resolved this tension.