Anyone who studies geography in any depth can see that different peoples and nations never had the same exposure to the progress of the rest of the human race. People living in isolated mountain valleys have for centuries lagged behind the progress of people living in busy ports, where both new products and new ideas constantly arrive from around the world.
If you study history in addition to geography, you are almost forced to acknowledge that there was never any realistic chance for all peoples to have the same achievements -- even if they were all born with the same potential and even if there were no social injustices.
Once I asked a class of black college students what they thought would happen if a black baby were born, in the middle of a ghetto, and entered the world with brain cells the same as those with which Albert Einstein was born.
There were many different opinions -- but no one in that room thought that such a baby, in such a place, would grow up to become another Einstein. Some blamed discrimination but others saw the social setting as too much to overcome.
If discrimination is the main reason that such a baby has little or no chance for great intellectual achievements, then that is something caused by society -- a social injustice. But if the main reason is that the surrounding cultural environment provides little incentive to develop great intellectual potential, and many distractions from that goal, that is a cosmic injustice.
Many years ago, a study of black adults with high IQs found that they described their childhoods as "extremely unhappy" more often than other black adults did. There is little that politicians can do about that -- except stop pretending that all problems in black communities originate in other communities.
Similar principles apply around the world. Every group trails the long shadow of its cultural heritage -- and no politician or society can change the past. But they can stop leading people into the blind alley of resentments of other people. A better future often requires internal changes that pay off better than mysticism about one's own group or about "social justice."