Franco-Thai War
Thailand took this opportunity of weakness to reclaim previously lost territories, resulting in the Franco-Thai War between October 1940 and 9 May 1941. The Thai forces generally did well on the ground, but Thai objectives in the war were limited. In January, Vichy French naval forces decisively defeated Thai naval forces in the Battle of Ko Chang. The war ended in May at the instigation of the Japanese, with the French forced to concede territorial gains for Thailand.