Some time before the middle of this century Europe ceased to be a self-regulating political system. This is much the most upsetting event in European history for centuries. It means that Europeans now look beyond their continental confines, not if and when and where they wish, but because they must. During the past 500 years or so—from the emergence of strong centralized French and English monarchies to the disruption of the polyglot empires of eastern Europe by self-determination—Europe has been increasingly articulated into secular sovereign states constructed and fuelled by national languages and national passions. These states have existed in a condition of conflict with one another. But their conflicts, however intense, were never perpetual, so that conflict itself became systematized and found its most characteristic expression in two things: in changes of alliance for the purpose of preserving the multinational system and in war. Europe was a political system which operated through alliances, reversals of alliances and war; and whenever one state threatened to become powerful enough to destroy or atrophy the system, there was always at hand an alliance of other states capable of checking its advance and ensuring the system's essential fluidity. There was, in consequence, no need to go outside the system in order to preserve it.