A 20-year-old U.S. citizen has been charged with planning to explode a car bomb at the U.S. Army’s Fort Riley in Manhattan, Kansas. According to FBI investigators, John T. Booker Jr. was making final preparations to carry out the suicide attack at the base on behalf of ISIS. Booker, who is also known as Muhammad Abdullah Hassan, had previously tried to join the U.S. Army but was denied entry because of Internet posts about “jihad” that first made news last year. The FBI said last year that it didn’t believe Booker posed an “imminent” threat. That apparently changed. Authorities say U.S. personnel were never in danger.