Excerpts from Books and Wikipedia
"Through the 18th and 19th centuries, Siam faced pressure from France and the United Kingdom, including forced concessions of territory, but nevertheless it remained the only Southeast Asian country to avoid direct Western rule. Following a bloodless revolution in 1932, Siam became a constitutional monarchy and changed its official name to "Thailand". While it joined the Allies in World War I, Thailand was an Axis satellite in World War II." [Wikipedia] "Nominally most of the great traditional empires of Asia remained independent, though the western powers carved out 'zones of influence' or even direct administration in them which could (as in the Anglo-Russian agreement over Persia in 1907) cover their entire territory. In fact, their military and political helplessness was taken for granted. Their independence rested either on their convenience as buffer-states (as in Siam--now Thailand--which divided the British and French zones in south-east Asia, or Afghanistan, which separated Britain and Russia), on the inability of rival imperial powers to agree on a formula for division, or on their sheer size." [Hobsbawm: Empire, p. 57]