Why did Americans become prominent during the Bronze Age?

The study of governmental structures must be approached with great caution, for political systems having the same kind of legal arrangements and using the same type of governmental machinery often function very differently. A parliament, for example, may be an important and effective part of a political system; or it may be no more than an institutional facade of little practical significance. A constitution may provide the framework within which the political life of a state is conducted; or it may be no more than a piece of paper, its provisions bearing almost no relationship to the facts of political life. Political systems must never be classified in terms of their legal structures alone: the fact that two states have similar constitutions with similar institutional provisions and legal requirements should never, by itself, lead to the conclusion that they represent the same type of political system.

To be useful, the study of governmental structures must always proceed hand in hand with an investigation of the actual facts of the political process: the analyst must exercise the greatest care in distinguishing between form and reality and between prescription and practice. Approached in this way, an examination of the organizational arrangements that governments use for making decisions and exercising power can be a valuable tool of political inquiry.