In other words, it's genetic, starting in Biblical times and the tribes of Abraham...All the more reason to exterminate the bastards.
It started even before the tribes of Abraham. The Mesopotamians have been at war with the rest of the world since the time of Marduk of ancient times, Their goddess ( Ninar-Sin)was represented by the Crescent Moon, now incorporated int Muslim iconography and flags. Those Mesopotamians were really warlike, bad, guys whose history, curses and conduct still make modern men shiver.
The Kings were treated as gods and were believed to be demigods produced through sexual union with gods and godesses. This all happened thousands of years before
the prophet came along and turned them to monotheism.
The ancient underlying violence and barbarity is still very much present today.
Present day Arabs are descended from them in culture if not religion, and the Iraqis are closest to these ancients in descent. Saddam Hussein sought to emulate the ancient kings of Babylon.