As well did Timurlane with those of the Hindu and Sikhs.
Genghis Khan, like any other imperialist, was a barbaric and ruthless monster to be hated by the conquered and the hero of the Mongols, even to this day.
To White, a good book on this subject is by Herald Lamb called "March of the Barbarians". The most interesting portion of this book is the relationship to today with the revival of Islam. There is a decidedly pointed and informative presentation using the Diary of Marco Polo to explain a personal dialogue Marco witnessed between Genghis Khan's grandson Kublai Khan and the chief Mullah within Khan's Yuan Dynasty during the 13th century.
"Once listening to a reading from the Koran, he discovered taht it laid a command upon Moslems to kill unbelievers. Summoning the chief Mullah to him, Khubilai asked if this were so. The teacher of Islam admitted it. "And you believe that this Koran has been given to you by G-d?" Khubilai demanded. The Mullah assented. "Then why do you not obey its command and slay those who do not believe as you do?" "Because the time has not come, and because we are unable to do it yet." "But I am able to do it," Khubilai assured him and ordered the execution of the Mullah." - March of the Barbarians by Harold Lamb page 267.
Further, persecutions and expulsions of the Mohammedans savages became policy throughout Cathay following this confrontation.
That's an interesting quote ! But Kublai Khan was not the savage murderer that his grandfather was, he was a civilized educated man. Unfotunately much of the Mongols, and especially the Turks, chose a different path, they embraced Islam. Tamerlane was a Tatar Muslim savage but he claimed (possibly correctly) to be a descendant of Gengis Khan.