All of the “world wars” were actually just European wars that stretched into the colonies. The concept of a “world war” is predominately western-centric.

But, regardless, if there was to be a third world war it would have to include the US as one of the major contributors. And it would, very likely, include both Russia and China on the other side.

Any war in Europe will be a NATO-Russian war, there’s little reason (as of the current) for EU countries to go to war with each other. There’s also little reason for the US to go to war with any of the EU countries, as they’re functionally satellites of the US (because of post-war investments the US made in Europe). If the US wants something in Europe, all they have to do is ask the right people. There’s no reason for them to lead a colour revolution or a coup there, so there’s no reason for tensions to be raised. The only remaining European country that’s a valid target for US aggression is Russia, and it’s likely the empire will swing wildly in Russia’s direction while it falls.

A third European war would not benefit Europe in the least, only the US and potentially the eastern powers. So it’s very unlikely that the European bourgeois class will support any aggression within their sphere, especially aggression from one of those beneficiaries.