Edward Alden: US 'Overreacted' to September 11th Attackbr World Affairs Council: Nor Cal - World Affairs Council of Northern Californiabr Since the attacks of September 11th, the United States has tried build new border defenses to keep out terrorists without stifling the flow of people and ideas from abroad that have built one of the world's most dynamic nations.But many of the new measures have instead cut America off from the world, punishing innocent people and discouraging the best and the brightest from coming here.