Siam/Thailand (Also an sort of an Empire)
Siam is aligned with Axis powers during WW2. That said, the direction Thailand could take can be interesting. In 1932, Thailand undergoes coup d'etat that place Khana Ratsudon party in power. This marked the end for absolute Thai monarchy. Originally led by a civilian (Nititada), he was ousted by another coup in April 1933 by Phahon due to communist accusation. October 1933 saw a bothced monarchist counter-coup. Later, Phahon resigned and replaced by Phibul in 1938. This was further consolidated by the aftermath of failed Songsuradet Rebellion in 1938, Phibul's own Night of Long Knives, according to Wiki.
Phibul is (somewhat) a fascist. His Thai Cultural Mandate contains several fascist-like point. He has ambition to unite all Thai people (which he defines as not just Southwest Thai,
but all of them). This is one of the cause of Franco-Thai War in 1940, which Thailand won after Japan meditated ceasefire (and France occupation by Germany). Originally the goal was all territories taken by France (Laos and Inner Cambodia IIRC), Japan trims the demand down. Neverthless, this war catapulted his popularity. No WW2 can means that France is more able to defends Indochina, thus fall of Phibun, slowly but surely if not by the hand of France governor themself
France probably won't turn Thailand colony or something like that. The Brits might get angry. At most, they'll take Isan highland
Phibul's fall of popularity will attract vultures. Luang, his chief propagandist, might double cross him. So does the left-leaning Pridi. But most likely, the the monarchy can't use this opportunity. The last king fled the country in 1935, the new King is in Swiss studying,
Due to no WW2, Thailand is not faced a question on whether to collaborate with Japan or not. Assuming Phibul survibed the Franco-Thai war, or it doesn't happen, the split between Khana Ratsudon and Seri Thai might not happens here, so probably Phibul won't get to be replaced by Pridi. Maybe deposed by coup after he dissastified the military perhaps, like his second, post war OTL term