Much of the world has been continually improving itself, beginning in the middle of the 19th Century. Note the key word much, however. Some parts of the world have not changed much at all.
Much of the Islamic world, for example, is determined to not change – and views this as a dangerous process that will take them away from the truth.
America, however, still continues to change at an ever-increasing pace – and this is extracting a heavy emotional toll from its people.
They have assumed, since they have been improved so much – they are now radically different people – in fact, demigods! And can take as much as they please, from lesser beings – everyone and everything else in the world.
This is faulty reasoning, but reasoning that seems perfectly sound to them.
Their critical reasoning has moved into their unconscious (including their collective unconscious). And this is typical unconscious reasoning – simple in its operation – and violent.