Adistinguished analyst of international politics, martin Wight, once laid it down as a fundamental truth of international politics that “Great Power status is lost, as it is won, by violence. A Great Power does not die in its bed.” But 12 years ago, the Soviet Union, a state not exactly averse to violence, confounded all expectations by doing just that. It sickened and quietly expired, without war or bloodshed.

When the communist superpower ceased to exist, it did more than bring the Cold War to an end. It also altered fundamentally the structure of the international political system. For the first time in its history, that system became unipolar. The United States became a global hegemon. While there have often been local or regional hegemonies – the Soviet Union in Eastern Europe, for example, or the United States in the Caribbean, and later in the Atlantic Alliance – there has never before been one that dominated the whole system.

How fundamental a change this is is indicated by the fact that one of the main themes in the history of the state system has been the repeated and determined efforts of alliances of states to prevent any of their number from achieving systemic hegemony, even at the cost of long and bloody wars. Phillip II of Spain in the 16th century, Louis XIV in the 17th and early 18th centuries, Napoleon at the beginning of the 19th century, the Emperor Wilhelm II of Germany and Hitler in the 20th century each tried for domination; all were eventually thwarted.