When we say "no war but class war", we mean that we'll never raise a rifle against "the evil hordes" of the other side, since we know those "hordes" are made of people just like us, proles. When we say "no war but class war" we understand that our rulers are as evil as the tyrant on the other side. That the crimes of one mirror the crimes of the other, that the elites, in their need to rule the world, know no boundaries to their cruelty. And that makes them equal.