I think the truth in this point lies in the fact that this was when the British Empire was still around and held large swathes of land with sway over large numbers of people.

That plus the German Empire lost large amounts of land after the great war.

It wasn't insane to pursue land. Not at that time.

The reasons, "science" and supremacism that surrounded it? Yes. Unfortunately, the kind that sweeps a broken, defeated nation under a spell, a mass delusion of grandeur.

I think they meant insanely unethical, which it is.

Insanely barbaric, when the "more room" part means taking it from other people. And when it's rationalized by racial and national mythology, then yes, it is absolutely insane.

This is still what drives politics today.

https://upload.wikimedia.org/wikipedia/commons/4/45/History_...

You have to get pretty creative to explain why the US are sprinkling missile interceptors ever closer to Russian soil without considering "mad power drive".