At exactly 5 p.m. on March 13, 2007, just as I was preparing to leave my cubicle in Washington for the day, I got a phone call from the journalist Jonathan Landay of McClatchy Newspapers. To this day, I remember his exact words. 'One of your congressman’s constituents is being held in an Ethiopian intelligence service prison, and I think your former employer is neck-deep in this.' The congressman was Rush Holt, then a Democratic representative from New Jersey, for whom I worked for 10 years starting in 2004. The constituent was Amir Mohamed Meshal of Tinton Falls, N.J., who...