It is often said that 9/11 has changed the world. Certainly, the world being swayed by the wars in Afghanistan and Iraq in the wake of that event appears to prove the saying correct.
But as far as the basic structure of today's international politics is concerned, the world underwent a drastic change when the Cold War ended. 9/11 served as a catalyst to make that structural change all the more manifest.
Then what kind of structure came to exist after the end of the Cold War? It goes without saying that a unipolar world order was born. But the problem is that a basic contradiction is inherent in this structure. The contradiction exists between the two components of this structure: first, a global hierarchy of power, particularly military power, which constitutes a pyramid of hegemony and disparity, with the U.S. at the top; second, a dynamic of universalizing the principle of equal rights of human beings, with the U.S. acting as the center for disseminating the message of global democratization.