Clearly, we need to do some gene manipulation to recreate the Neanderthals, so Homo Sapiens can turn this messed up world back over to them.
Nearly every square meter of land on earth (aside from some parts of the Polar regions) was once occupied by people who were forcibly driven out or marginalized. That means, practically everyone is an "invader", or the descendent of an invader. At what point do you stop trying to enforce prior rights? At what point is it insane to even attempt to rectify the past? How many hundred million people do you need to move?
My ancestors were from Hungary. After Austria-Hungary's defeat in WWI, Austria was punished by having its ethnic minority regions spun off, as well as having 100% of its coastline taken away (most of it given to Italy) to prevent it from ever becoming a naval power again. Once liberated from Austria, Hungary's situation was technically "questionable" as to whether or not they were still "at war", and whether the surrender of Austria-Hungary applied to independent Hungary, which had already disarmed according to the terms of the A-H surrender. Months later, the various commissions set up by the Allied powers decided to create new homelands for ethnic minorities, many of which had emigrated into Hungary over the previous centuries. In the ensuing Trianon Treaty, 60% of Hungary was taken away, and split up between Czechoslovakia, Romania, and Yugoslavia, mostly done by people with no understanding of the economic and logistical considerations on the ground, as opposed to what looked good on a map. Hungary's repeated attempts in the League of Nations to schedule plebiscites for the people in former Hungarian territory to establish which county they wanted to live in were rudely rebuffed. Czechoslovakia threatened to invade over it, claiming that requesting a plebiscite was "warmongering" by an almost completely disarmed nation. "Self-determination" wasn't the reason, otherwise plebiscites would have established the will of the people living in the disputed areas in the matter. 20 years later, when WWII broke out, Hungary was lumped in with the Axis powers for wanting its own people back, and forced to choose between siding with Germany or the Soviets. It didn't end well.
At this point in time, a century after the dismemberment of the country, those lost areas are mostly (not entirely, it seems) integrated into their respective new countries, and I consider Hungary's claims as having lapsed. Injustice was done (yes, Hungary itself had taken the land 1000+ years ago from people who had also taken it centuries earlier), but at this point, it's too late and too convoluted to correct ANY of those injustices.
One can try to prevent injustice when it happens, or in cases where it's possible, try to seek compensation or justice for those who were deprived within their own lifetimes, but anything beyond that becomes increasingly complicated and absurd. Giving reparations to the great-grandchildren of a deprived populace does nothing to help those who actually suffered, and merely stokes resentment and discrimination against those descendants.
