"Since the September 11 attacks, the U.S. government has spent $2.2 trillion to finance the wars in Afghanistan and Iraq, according to figures from Brown University's Costs of War Project. Yet that sum — which amounts to roughly 10% of the country's total gross domestic product — only reflects upfront costs. Including the cost of interest on those wars will add an additional $2.1 trillion by 2030. And through 2050, the interest alone is forecast to top $6.5 trillion — even if war spending had theoretically stopped in 2019, according to research published last year from Heidi Peltier, director of the "20 Years of War" Project at Boston University's Pardee Center for the Study of the Longer-Range Future. Such borrowing leads to larger total costs because interest must be paid as long as the debt is owed. That pushes the "true cost of war out to future generations," Peltier told CBS MoneyWatch. "What that does is shield the American public from the costs currently," she said. "So, Americans don't realize that they're paying for the cost, because their taxes are not increased. And they're not buying more [war] bonds, they're not in any way feeling the [financial] effects currently.""