This map, taken from the Records of the Central Intelligence Agency (CIA), shows the disposition of communist troops in and immediately around Vietnam (then commonly known as Annam) as of Dec. 13, 1950.
What will likely jump out at onlookers are the Chinese forces massed near the border area as well as the arrows demonstrating routes of approach used by Viet Minh revolutionaries to enter Vietnam from training areas located in China. The map notes that an estimated 30,000 Chinese troops nearest to the border are “irregulars”—in other words, guerrilla forces. What is also noteworthy is the extent to which the Viet Minh had gained territory by that time.
This historical map taken from CIA files presents an interesting visual snapshot of Chinese military support for Vietnamese insurgents during that time.