I don't know the exact date they declared war but it would have been within a few days of Pearl Harbor. As for why, it is necessary to understand how Canadians percieved themselves at that time. Canada had been British territory since the 1750s. As time had gone on Canada had very gradually achieved self government, in all respects including foreign policy, without ever formally becoming independent of Britain. This status was called being a British Dominion. This meant a fully soveriegn state *within* the British Empire. Thus, the way Canadians looked at and defined themselves was as a part of the British Empire. Hence, when England declared war on Japan immediately after Pearl Harbor, actually doing so before even the United States, Canada, which was already at war with Germany for the same reasons, declared war also. Michael Montagne
In the late evening of December 7, 1941, the Canadian Prime Minister, W. L. Mackenzie King, announced the Cabinet's decision to declare war on Japan. The King approved Canada's declaration of war in the following proclamation issued on December 8, 1941.
Whereas by and with the advice of our Privy Council for Canada we have signified our approval of the issue of a proclamation in the Canada Gazette declaring that a state of war with Japan exists and has existed in Canada as and from the 7th day of December, 1941.
Now, therefore, we do hereby declare and proclaim that a state of war with Japan exists and has existed as and from the seventh day of December, 1941.
Of all which our loving subjects and all others whom these presents may concern are hereby required to take notice and to govern themselves accordingly.
The US was forced to declare war on Japan in DECEMBER 9, 1941
It was FDR not Teddy on 08 Dec 1941
CANADA
Japan attacked Pearl Harbour on December 7, 1941 ('a date which will live in infamy'). The US declared war on Japan the following day, December 8, 1941.
Japan, bro. Japan declared war on America not Germany. Canada declared war on Germany on the 10th of September.
December 7, 1941
The US was forced to declare war on Japan in DECEMBER 9, 1941
December 8, 1941.
December 8, 1941
the us didn't declare war on china in world war 2 us declared war on japan on 1941 when japan bombed pearl harbor hawii
It was FDR not Teddy on 08 Dec 1941
On December 8, 1941, the day after Pearl Harbor was bombed.
CANADA
Yes. The US declared war on Japan on December 8, 1941, one day after the attack on Pearl Harbor.
Japan attacked Pearl Harbour on December 7, 1941 ('a date which will live in infamy'). The US declared war on Japan the following day, December 8, 1941.
they were attacked by japan in pearl harbor Hawaii in December 7 1941 but declared war dec. 8 1941
December 8, 1941.The day after the attack on Pear Harbor.