Shan Carter and Amanda Cox of the New York Times explore the total financial cost of Al Qaeda’s 9/11 attack ten years ago. In today’s dollar, their final tally is $3.3 trillion in and by the United States alone:
Al Qaeda spent roughly half a million dollars to destroy the World Trade Center and cripple the Pentagon. What has been the cost to the United States? In a survey of estimates by The New York Times, the answer is $3.3 trillion, or about $7 million for every dollar Al Qaeda spent planning and executing the attacks. While not all of the costs have been borne by the government — and some are still to come — this total equals one-fifth of the current national debt.
The interactive from which the above screenshot is taken explores war (and future war) funding, homeland security, economic consequences, veterans care and actual physical damage from the attacks.