Today’s strategic environment is characterised by persistent competition between states, most of all between the West, Russia and China, but also more broadly as nationalist narratives gain traction in many key middle powers. While this competition does not itself lead to war, it makes the international system more vulnerable to unpredictable shocks. Today, some of the most worrying potential shocks are those often characterised as being ‘grey zone’ – intended to be below the threshold that risks triggering a broader conflict. There can be no all-out winners in the competition between NATO, Russia and China. Nor is its end in prospect any time in the foreseeable future. Rather we can look forward to frequent, and continuing, probing and opportunistic behaviour – subversion, espionage, assassinations, designed to gain tactical advantages in the ongoing struggle.