NATO is not ready to mitigate increasingly prevalent Russian aggression against European critical undersea infrastructure (CUI). Despite its depleted ground forces and strained military industrial base, Russian hybrid tactics remains the most pressing threat to CUI in northern Europe. Despite its current limitations, NATO is the primary actor capable of deterring and preventing hybrid attacks on its allies and has expedited its approach to CUI protection by establishing new organizations to that aim. At the 2023 NATO Vilnius summit, allies agreed to establish the Maritime Centre for the Security of Critical Underwater Infrastructure within NATO’s Allied Maritime Command (MARCOM), which focuses on preparing for, deterring, and defending against the coercive use of energy and other hybrid tactics. To help NATO planners and staff at the new center conceptualize and prioritize their efforts, this issue brief provides immediate and long-term recommendations to set the new center up for success.