 In early 1940, troops of the Imperial Japanese Army (IJA) moved to seize southern Guangxi and Longzhou County, where the eastern branch of the Kunming–Hai Phong Railway reached the border at the Friendship Pass in Pingxiang.They also tried to move west to cut the rail line to Kunming.The railway from Indochina was the Chinese government's last secure overland link to the outside world.