As tragic as the terrorist attacks of September 11, 2001, were, it was America’s response that truly changed the world. While it is difficult to pinpoint precisely which developments over the last 25 years were caused or compounded by 9/11, it seems clear that the event led the United States to abandon the principles that, with the Cold War over, were supposed to shape a better future.

Richard Haass argues that the terrorist attack 25 years ago, though horrific, did not change the course of history.

As tragic as the terrorist attacks of September 11, 2001, were, it was America’s response that truly changed the world. While it is difficult to pinpoint precisely which…