Japanese Invasion of Thailand (Yellowstone: 1936)

The Japanese invasion of Thailand occurred on 14 December 1941. It was fought between Thailand and the Empire of Japan. Despite fierce fighting in Southern Thailand, the fighting lasted only a few hours before ending in a ceasefire.

Background
As Japanese forces began their assault on Pearl Harbor, Hong Kong, and other allied positions, the Japanese sought to begin an invasion of Malaya and Burma. In order to do this, the Japanese would need to utilize Thai ports, railways, and airfields, operating as a springboard into the rest of Southwest Asia. Japanese attempts to negotiate an agreement with Thai Prime Minister Phibun Songkhram, in which the Japanese military sought free passage through Thailand, ended with uncertainty, and acted to further warn the British of a potential attack looming against their possessions in Southeast Asia.

Although the Thai had a well disciplined army, experienced following the 1938 invasion of Indochina, Phibun could have considered he had little choice, as his own forces would have been unable to defeat the Japanese alone. The Japanese invasion was launched on 13 December 1938. Japanese troops invaded Thailand from Indo-China, landings soldiers south of Bangkok and at various points along the Kra Peninsula. At the time of the invasion the Thai government was unable to contact Songkhram, their Prime Minister. The Japanese invasion force was divided between the 15th and 25th armies, with each in charge of a different set of objectives.

Overview
Following the initial attack, the Imperial Japanese Army 33rd Division under Lieutenant-General Shōzō Sakurai and the Imperial Japanese Army 55th Division under Lieutenant-General Hiroshi Takeuchi of the 15th Army, spearheaded by the Imperial Guards Division, crossed the border from Indo-China into Thailand's recently reclaimed Phra Tabong Province at Tambon Savay Donkeo, Athuek Thewadej District (Russei) of Battambang. The Japanese encountered no resistance in this area, and from Sisophon swung north-westwards into Aranyaprathet, which remained still a district of Prachinburi Province at the time, along the finished railway link between Aranyaprathet and Monkhol Bourei.

The Japanese 1st Infantry Battalion of the 143rd Infantry Regiment, part of the Imperial Japanese Army 55th Division, landed at Chumphon. After forming a small perimeter around their landing site they became pinned down by determined resistance, consisting of the the 52nd Youth Army Training Unit from Sriyaphai School and the 38th Infantry Battalion and Provincial Police of Chumpon. During the fighting Thai Captain Thawin Niyomsen was killed, as was several provincial police and a few civilians.

Another Japanese landing would take place at Nakhon Si Thammarat, the site of the Thai Sixth Army Division’s Headquarters and 39th Infantry Battalion. Three Japanese troopships, Zenyo, Miike and Toho Maru's, land troops at Nakorn Sri Thammarat, S Siam, covered by the Shimushu, dropping anchor a few kilometres off the coast during the night of December 10. The invading force of 1,510 men and 50 trucks of the 3rd Infantry Battalion of the 143rd Infantry Regiment, the 18th Air District Regiment along with an army air force signals unit, the 32nd Anti-Aircraft Battalion, and the 6th Labour Construction Company, began disembarking their troops at the Tha Phae canal (also known as Pak Phoon Canal), North of Camp Vajiravudh, to which the landing was made adjacent. Receiving news of the invasion at Songkhla, the Thai forces immediately went into action, fighting until the end of the invasion.

Aftermath
Similar invasions would be launched across southern Thailand, supported by air craft overhead who worked to bomb major cities and strategic positions. Plaek Pibulsonggram finally made the decision to sign an armistice with Japan effectively ending any chance of Thailand joining the allied forces. He also granted Japan permission to use Thailand as a base of operations to invade Malaya. Within hours after the armistice came into effect, squadrons of Japanese aircraft had flown into Songkla airfield from Indochina, allowing them to carry out air raids on strategic bases in Malaya and Singapore from a short distance. At the time of the ceasefire, Britain and the other Allied powers regarded Thailand as Japanese-occupied territory.