Genghis Khan recognized that warfare was not a sporting contest or a mere match between rivals; it was a total commitment of one people against another.
Victory did not come to the one who played by the rules; it came to the one who made the rules and imposed them on his enemy. Triumph could not be partial.
It was complete, total, and undeniable—or it was nothing.
In battle, this meant the unbridled use of terror and surprise.
In peace, it meant the steadfast adherence to a few basic but unwavering principles that created loyalty among the common people.
from Jack Weatherford's 'Genghis Khan and the Making of the Modern World'
https://www.amazon.com/dp/1491513705/ref=cm_sw_r_tw_dp_x_-ZKfAbM3YRVMJ