1942 to 1945. During the first year of the campaign (December 1941 to mid-1942), the Japanese Army (with aid from Thai Phayap Army and Burmese insurgents)
for four more months. After the Japanese failure to penetrate the Bataan defensive perimeter in February, the Japanese conducted a 40-day siege. The crucial
of the United Kingdom declared war on the Empire of Japan on 8 December 1941, following the Japanese attacks on British Malaya, Singapore, and Hong Kong