Last world war was started by 1 country. People always forget it takes only one dide to start a war, it will start even if the other side refuses to fight. Poland Czechoslovakia, France...

Whether you like or not, we are in a world war. Russia send it's agents to blow up ammo depots (Czechia), mobilizes it's fifth collumns (Baltics), uses it's proxy states to attack NATO members (Belarus) and uses propaganda and financial ties to weaken Western unity.

The actual war is between Ukraine and Russia, but the rest of the war is in proxy war too. Even in WW1 and WW2, not all countries were fighting on the front, but were part of the conflict. As the West is now.