A country or people is only entitled to the land for as long as they can defend it, utilize it, and govern it.
Countries have been attacking and taking over territories, people, and countries for as long as there have been humans.
The weak cultures, people, and countries die. The strong survive.
Does that make it ethically right to invade? No.
Is the reality of the world we live in such that most countries in an effort to improve the situation for their people either physically invade, or economically or culturally invade others?
Yes.
Hell it's happening to us at the border and culturally with socialism, wokism, and China influencing everything we do.
If our people and ideals are not strong enough to survive the onslaught because we have become a weak and ineffectual people, then it is better for the world and humanity if we fall to the wayside to make room for something better.