Also a provocation that forces a reaction that is difficult to modulate. Activating Article 5 demonstrates NATO solidarity and that it means business, but it would be disastrous. Doing nothing demonstrates fecklessness and impotence of NATO. The reaction needs to be measured and proportionate.

But outright hostility is not necessarily the goal. Hybrid warfare is more “subtle”. Its targets are more diverse and the aim is less overt defeat and more war of attrition in a broad sense. You want to wear your enemy down.