In his book The Anarchical Society:A Study of Order in World Politics,Hedley Bull defined international order as a behavior pattern resulting from pursuit of purposes by nations or the international community. Scrutiny shows that stark nation-centralism has been the guiding factor behind the theories and practices of international relations in modern times--the Westphalia,Vienna,Versailles and Yalta systems.Even contemporary international order has not been free from fetters of nationalism.