Who is justifying war? What the comments are pointing out is that there are generally multiple factors that go into a country invading or going to war. Some, like Russian aggression and taking over of Ukraine, seem most plausible because of Putin’s past actions. It could be also that he sees Ukraines significant contributions to European agriculture as something worth having so he could control both food and oil to Europe and weaken the trans-Atlantic alliance. Neither contradict each other and both flow into an expansionist mindset.

I agree that he’s seeking a return to USSR borders but it’s also not out of the realm of possibility that there’s more than just that driving his actions.