For Thailand – renamed from Siam in 1939 – the Second World War involved both the bilateral struggle between the Axis and Allied forces in the region and the regional struggle across Southeast Asia between historic rivals. Like other regional actors, Thailand – under military rule following the coup of 1932 and led by Prime Minister Major-General Plaek Pibulsonggram (popularly known as "Phibun") – was to exploit the changes in power caused by the fall of France and the expansion of Japan to attempt to offset the losses of the previous century. Thailand's considerable investment in her army, based on a mixture of British and German equipment, and her air force – a blend of Japanese and American aircraft – was about to be put to use.