The event was Germany invading Poland.
The US was forced to declare war on Japan in DECEMBER 9, 1941
Japan
The immediate cause was Japan's attack on Pearl Harbor. This caused the US to declare war on Japan, which led to Germany and Italy declaring war on the US.
The United States was bombed by the Japanese at Pearl Harbor which cause a declaration of war but Germany had an alliance with Japan and it had forced the United States to declare war on Germany too. Then Germany had an alliance with Italy which cause the United States to declare war on yet another country. Then the world was at war and therefore World War 2 started.
the German capital would be divided into four partsApex
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
On Japan.
Any country can declare war on anybody else. What matters is can you back it up?
after japan attacked pearl harbor and declared war on japan a German Allie
The British declared war on Germany during World War I because Germany violated Belgian neutrality by invading Belgium in August 1914, which was seen as a threat to British interests and potential aggression towards Britain. In World War II, the British declared war on Germany after Germany invaded Poland in September 1939, triggering Britain's declaration of war to honor their commitment to defend Poland's sovereignty.
Because of Pearl Harbour.