Activists meet in the Nam Can forest, wearing masks to hide their identities from one another in case of capture and interrogation. From here in the mangrove swamps of the Mekong Delta, forwarding images to the North was difficult. "Sometimes the photos were lost or confiscated on the way," said the photographer.
IMAGE: VO ANH KHANH/ANOTHER VIETNAM/NATIONAL GEOGRAPHIC BOOKS
New recruits undergo physical examinations in Haiphong. The North's volunteer system was transformed into a mandatory system in 1973, when all able-bodied males were drafted. From a corps of around 35,000 men in 1950, the NVA grew to over half a million men by the mid-'70s, a force the U.S. military conceded was one of the finest in the world.
IMAGE: BAO HANH/ANOTHER VIETNAM/NATIONAL GEOGRAPHIC BOOKS