In the early 1990s Muslims were engaged in more intergroup violence than were non-Muslims, and two-thirds to three-quarters of intercivilizational wars were between Muslims and non-Muslims. Islam's borders are bloody and so are its innards.

Ch. 10 : From Transition Wars to Fault Line Wars § 3 : Incidence: Islam’s Bloody Borders p. 258 * Footnote 10: No single statement in my Foreign Affairs article attracted more critical comment than: "Islam has bloody borders." I made that judgment on the basis of a casual survey of intercivilizational conflicts. Quantitative evidence from every disinterested source conclusively demonstrates its validity.