A Pennsylvania Air National Guardsman is facing federal charges after allegedly building explosives, promoting extremist violence, and vandalizing a Jewish synagogue. The indictment names three defendants, including the Guardsman, who made false statements about his loyalty to the U.S. while privately expressing support for terrorist groups. The defendants are also accused of conspiring to manufacture and possess destructive devices. The FBI and other agencies are committed to investigating individuals who engage in dangerous and illegal activities.