Russia’s war in Ukraine since February 2022 has been accompanied by a significant increase in cyber attacks in Europe and among NATO member countries. What difference do cyber operations make to the ongoing war between Russia and Ukraine, and to contemporary conflicts more generally? Is there a link between cyber and nuclear deterrence, and if so, what is it? Who are the players in cyber wars? What specific challenges does this type of conflict pose in terms of sovereignty or strategic autonomy? To mark the launch of its cyber cluster, CIENS is organising a round-table discussion to examine these questions and offer some food for thought for the future.