In 1941, following Japan's invasion of Burma, parts of Burma were ceded to Siam as the Saharat Thai Doem territory, thereby ending the existence of the Laos-Myanmar boundary, however these areas were returned to Burma in 1946 following Japan's defeat and the boundary restored. In 1937 Burma had been separated from India and became a separate colony, gaining full independence in 1948. Laos obtained a partial independence from France in 1949, gaining complete independence in 1953, with the boundary then becoming one between two sovereign states. The border region became unstable in the subsequent decades, with various armed groups operating here, such as the Chinese Kuomintang, Pathet Lao and various Shan militias. The border is nowadays more peaceful - a joint demarcation survey of the border was conducted in June 1993, and a Friendship Bridge across it was built in 2015.