So what do we do, how far back does the violence have to have occurred to be "legit" or "forgotten". Currently we see the Russians, the Ukrainians, the Israelis and the Palestinians dig out various maps from various times in the past that show all sorts of things, each one in their favor.

It seems that there is some sort of consensus by the "international community" whoever that is that draws the line post WW2 1950-ish and those are the official borders now and they stay forever.

Seems pretty arbitrary to me.