As President Biden prepares to lay out his plan Wednesday to withdraw US troops from Afghanistan and end America’s longest war, a source familiar with his thinking tells me that he thinks no amount of US troops in the country can be a game changer anymore.As President Biden prepares to lay out his plan Wednesday to withdraw US troops from Afghanistan and end America’s longest war, a source familiar with his thinking tells me that he thinks no amount of US troops in the country can be a game changer anymore.