Koh Chang — the Franco-Thai War

France's defeat has whetted the appetites of her neighbors in Asia. Marshal Phibun's Thailand, encouraged by Japan, demands the return of Laotian and Cambodian territories once ceded to French Indochina and, in late 1940, attacks those frontiers. Admiral Decoux, isolated Governor-General and cut off from any reinforcement, has only meager means against a Thai army and air force superior on the ground.

One asset remains: at sea, the small French squadron is the better trained. Capitaine de vaisseau Bérenger has the old cruiser Lamotte-Picquet and a few sloops. Intelligence reports a concentration of the Thai fleet — including two modern coastal defense ships — anchored near the island of Koh Chang, in the Gulf of Thailand.

Bérenger must decide what stance to take: risk an offensive raid against a fleet at anchor, with an old ship and no support, to restore morale and slow the adversary; stay on the defensive to cover Saigon; or wait for instructions from a distant and powerless Vichy. Boldness might offset the general French weakness in Indochina.