More from the Weinberger piece

Utterly fascinating...

In 1206 a Mongol of obscure birth, Temujin...

Within a few decades he [Ghengas Khan--"universal ruler"] and his successors controlled an empire that stretched from Korea to Poland. They destroyed dynasties that had governed for centuries...Samarkand and Bukhara never recovered their glory; in the Silk Road city of Merv, perhaps the largest in the world, a million and a half people were killed...800,000 were killed in Baghdad; a million in Chengdu...in Poland they cut off one ear of every surviving male and collected them in bags. It was merely the fortuitous deaths of [Ghengis's] successors that kept them out of Egypt and Europe all the way to the Atlantic.

The Mongols overran one fifth of the earth with forces inferior in number, but unmatched in military tactics and political skill...Unlike the Arab nomads who conquered in he name of Islam or the European Crusaders who fought for Christ, the Mongols had no ideology. They founded no civilization; they only devastated cultures or let them be.