Critical infrastructure is on the front line of the war in Ukraine. And as the conflict approaches its fourth year, there is little sign of that changing. Strikes against infrastructure, though, are only part of the picture. Since Russia’s full-scale invasion, and even before, Ukraine’s defenders have waged an equally intense, but less visible, cyber war. What lessons can we draw from Ukraine’s experience? And how can states and businesses protect their critical national infrastructure during war and conflict? And how do the public and private sector deal with the prospect of both kinetic and cyber threats? We discuss this with Mihoko Matsubara, author, associate fellow at the International Institute of Strategic Studies and chief cybersecurity strategist at NTT Corporation.