How War was changed to eliminate the most intelligent and brave that would otherwise challenge TPTB.

The most Courageous, ethnocentric and intelligent of the winners die disproportionately in war. However, the elimination and replacement of the losers that exhibited less of these traits is even greater.

Thus war would increase ethnocentrism and intelligence (which lead the personality traits that are necessary to organize, sacrifice and cooperate for common interests such as not falling prey to a cabal) of the two populations (as a whole) at war.

In more recent history, the conquerors would no longer genetically replace the defeated, thus the positive selection was removed, and now all that is left is the death of honorouble (more proportionately represented in upperclass) man. Now war reduces the positive traits limiting the ability of an evil cabal to impoverish or enslave humans. The middle class is individualistic and more prone to betraying their ingroup whereas upperclass (now mostly dead) were nobless oblige warriors.

By Eliminating intelligence, positive personality factors, and ethnocentrism. The PTB now have a population less capable of challenging them (less bravery, group identity and intelligence), and easier to manipulate (lower intelligence).

Needless to say, you'd be familiar with the racial replacement and possibly other measures in weakening the population.

If you did watch the video, let me know your thoughts!

Edit: video was created by The Jolly Heretic (not me)