According to the West, Russia is the aggressor.
- The UN Charter has provisions for collective self-defense under the UNSC umbrella. This happened in the Korea War, because the Soviets were boycotting the UNSC at the time and China was still represented by the ROC government.
- As it is generally understood, these provisions for UNSC-led collective action do not replace the older rights for collective self-defense, they merely augment them. Any state is allowed to assist Ukraine in their defense by joining the war between Russia and Ukraine. They could do that in Ukraine or anywhere else in the world (e.g. on the high seas, or in Siberia).
- By assisting Russia, North Korea may be joining that war of aggression. This depends on the exact status of their personnel. There seem to be indications that they're fighting in Russian uniforms, which might give North Korea some deniability.
According to Russia, the West is the aggressor and at war with Russia.
- State-sponsored propagandists use 'at war' while diplomats refrained from clearly declaring that 'a state of war does exist.'
- Russia may have taken covert actions which would constitute acts of war against various NATO states and within the NATO treaty area if they were clearly attributable to Russian government agencies.
The NATO members have chosen to support Ukraine in ways which are no acts of war (according to their interpretation of international law), because they do not want the war to spread beyond Russia and Ukraine. They could offer wider-ranging support, but that might escalate the war in ways they do not want.
