One of the greatest contributions made by the Seri Thai was the intelligence gathered about Japanese intentions and movements, which resulted in direct allied military efforts at critical points of the war. As the Japanese began their Burma campaign in 1942, perhaps the most important military operation in South Asia during the war, information followed freely from the front lines back to communication points established by Seri Thai operatives in the north and west frontiers of Thailand. Intelligence was gained about Japanese supply lines, base locations, troop size and strength and military objectives.