Teens waved terrorist flags and learned Maoist war tactics at a radical “Anti-Imperialist Summer Camp” hidden in the Pacific Northwest, The Post has learned. The late August camp, run by the terror-linked Anti-Imperialist Front USA (AIF-USA), was attended by teenagers from their offshoot, Revolutionary Youth, along with community college students and young workers, in the Pacific Northwest, according to materials provided to The Post by education watchdog group the North American Values Institute (NAVI). Pictures from the trip showed nearly 20 hoodie- and bandana-clad campers sitting around a fire alongside flags from several terrorist groups, one of which read “Victory...