evidence: That is the guiding principle behind my decisions about Afghanistan. I simply do not believe that the safety and security of America is enhanced by continuing to deploy thousands of American troops and spending billions of dollars a year in Afghanistan. [...] After more than $2 trillion spent in Afghanistan — a cost that researchers at Brown University estimated would be over $300 million a day for 20 years in Afghanistan — for two decades — yes, the American people should hear this: $300 million a day for two decades.