"An Augury of the Anti-Liberal Politics and Virulent Nationalism That Would Soon Reach Around the World, Even to America"

"Two decades after September 11, we're no longer those Americans who believed such things would never happen to us, and who, when they did happen, went boldly overseas to rid the world of monsters. Experts now see white-nationalist terrorism as a greater domestic threat than Islamist terrorism. The new fight is for our own democracy. It will require all the restraint and purpose and wisdom that we struggled to muster when the enemy wasn't us."

George Packer at The Atlantic writes that 9/11 "was the first sign that the 21st century would be a period of shock and disaster."

And Calvin Woodward, Ellen Knickmeyer, and David Rising of the AP discuss the event's impact.