Winston Churchill Malaya Singapore Hong Kong the UK declared war on Japan Germany declared war declared war on Japan Italy United Kingdom United States
The United Kingdom had already been at war with Germany since September 1939 and with Italy since June 1940, and British Prime Minister Winston Churchill had promised to declare war "within the hour" of a Japanese attack on the United States. Upon learning of the Japanese attacks on Malaya, Singapore, and Hong Kong, Churchill promptly determined there was no need to either wait or further consult the US government and immediately summoned the Japanese Ambassador. As a result, the UK declared war on Japan nine hours before the US did.
