In 1953, when the Pathet Lao, which rebellion expended dangerously, occupied the region of Phongsali, while its allied Việt Minh troops managed to control the Tonkin penetration axes to North, threatening the royal capital Luang Prabang, Laos fully entered into the First Indochina War. On October 23, 1953, a Treaty of Amity and Association was signed and France committed to defend Laos against the advance of communist troops. A garrison assigned under the command of General Henri Navarre – whose mission was to prevent any Việt Minh infiltration to Laos – was implanted in a strategic area, in West Tonkin, close to the Laotian border, where were some important runways connecting Luang Prabang to Diên Biên Phu Basin.