Clearly, the Islamic State''s particular brand of brutality derives from the deeply dysfunctional and violent politics of the Arab states it has fought in Iraq, Syria, Libya and Egypt. The special irony, however, is that it proved far more adept than these foes at demonstrating strategic flexibility and at systematically instilling tactical autonomy, initiative, and unceasing offensive action among its fighters down to the lowest rank.?Ashour''s excellent,?methodical dissection of?this fluid interaction of strategy and tactics provides a compelling explanation of how Islamic State fighters repeatedly won?and endured?against overwhelming odds.