Whydid the US declare war on japan?
December 8, 1941
Germany, Italy and the other minor Axis nations. The only nation the US did declare war on was Japan, the day after Japan attacked the US Naval Base at Pearl Harbor. Three days after the US declared war on Japan, Germany and Italy declared war against the US. That was enough to bring about a state of war between the US and Germany and Italy. There was no need for Congress to declare war back.
The US did not declare war on Germany and Italy, although it would have been justifiable to do so since they had a formal alliance with Japan. The US declared war on Japan. A few days later, Germany and Italy declared war on the US. The above answer is missing an important factor in all this: America was the only country Germany declared war on! Germany, Italy and Japan formed the Axis, and as Germany…