We live in what international relations specialists call 'a unipolar moment'. They mean that the US is the uncontested leader in world politics. It is hard to argue with that, but where does that power come from?
Some credit the country's military. By that standard, America is second to none, today or in history. The US defence budget for the 2004 financial year is US$399.1 billion, almost as much as the combined spending of almost every other nation. That might help the US fight and win wars, but it is not the real foundation of American power. The Soviet Union had a military that matched and sometimes exceeded that of the US - including its nuclear arsenal - but that did not prevent its collapse. Winning a war is relatively easy compared to winning the peace, as events in Iraq demonstrate.
Realists counter that the military matters when it is backed by a powerful economy. The Soviet Union collapsed because it could not support the voracious appetite of its military machine. The United States accounts for a quarter of the global gross domestic product and is one of the drivers of growth worldwide. They point to that economic dynamism as the real foundation of American supremacy.
This explanation is better, but it is still incomplete. US economic vitality is a necessary condition for its status, but it is not sufficient to explain US leadership. The focus does not belong on wealth per se, but on the conditions that allow Americans to turn human potential into prosperity: rule of law, equal opportunity and liberty.
The association of those qualities with the US is what the theorists call 'soft power'. Joseph Nye, dean at Harvard's Kennedy School of Government and sometime government official, has popularised the notion. For him, 'soft power is the ability to get what you want by attracting and persuading others to adopt your goals'. He does not mean favouring carrots over sticks. That is far too crude. Rather, Professor Nye is referring to the power of ideals, culture and values to shape perceptions. In the US context, it is the identification of the US with justice, equality and democracy that has buttressed American leadership. People around the world like and aspire to those ideals. They support the US because it has worked to realise them worldwide. Crudely put, people think of the Americans as 'the good guys' and aspire to be like them.
The visible manifestation of the soft power of the US is apparent in the popularity of American movies, music and books, the receptivity of other countries to its trends, its fashions, the American way of thinking and its way of life.
This explanation for American power makes sense. The west did not win the cold war because it stared down the Soviets; the Soviet empire eroded from within. The Helsinki process, which opened the east and exposed those citizens to western values, was the instrument of victory - not the vast arsenal of nuclear-tipped missiles.