The Japanese invasion of Thailand (, ; ) occurred on 8 December 1941. It was briefly fought between the Kingdom of Thailand and the Empire of Japan. Despite fierce fighting in Southern Thailand, the fighting lasted only five hours before ending in a ceasefire. Thailand and Japan then formed an alliance making Thailand part of the Axis alliance until the end of World War II. Background Hakkō Ichiu The origin of Japanese invasion of Thailand can be traced to the principle of hakkō ichiu as espoused by Tanaka Chigaku in the mid- to late-1800s. Tanaka interpreted the principle as meaning that imperial rule had been divinely ordained to expand until it united the entire world. While Tanaka saw this outcome as resulting from the Emperor's moral leadership, Japanese nationalists used it in terms of freeing Asia from colonizing powers and establishing Japan as the leading influence in Asia. The concept became expressed in the . In 1940, the concept was expanded by Prime Minister Fumimaro Konoe, who sought to create the Greater East Asia Co-Prosperity Sphere, including Japan, Manchukuo, China, and parts of Southeast Asia. This would, according to imperial propaganda, establish a new international order seeking "co-prosperity" for Asian countries which would share prosperity and peace, free from Western colonialism and domination under the umbrella of a benevolent Japan. The 30 man Number 82 Section (also known as the Taiwan Army Research Unit or Doro Nawa Unit) Strike South planning was formed in 1939 or 1940 to bring this about. In its final planning stages, the unit was commanded by Colonel Yoshihide Hayashi. Prelude As part of conquering Southeast Asia, the Japanese military planned to invade Malaya and Burma. In order to do this, they needed to make use of Thai ports, railways, and airfields. They did not want conflict with the Thai military, as this would delay the invasion and significantly reduce the element of surprise. The Japanese plan was seen by the Nazi government of Germany as helpful in diverting the United Kingdom's military forces, and thus assisting Germany in its own conflict. Thailand had a well-disciplined military, and after a series of border skirmishes in 1940 had invaded neighbouring French Indochina to recover provinces lost in the Franco-Siamese War of 1893. The Japanese, who wanted to use the Indo-Chinese ports and air-bases, acted as negotiators to bring about a settlement between the French and Thais on