The United States needs a new national security strategy to prevent the spread of extremism in fragile states, the co-chairs of the 9/11 Commission warn in a new report. The report entitled “Beyond the Homeland: Protecting America from Extremism in Fragile States,” is released Tuesday on the 17th anniversary of the 2001 terrorist attacks to address the 9/11 Commission’s unfulfilled call for the U.S. to  adopt a preventive strategy to reduce the spread of extremism.