No.
Pearl Harbour.
Germany
On Japan.
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
Atomic weapons negate declarations of war.
mostely politcical problems
only on US
on decmber 8 1941
neutral
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.
No, and the US did not declare war on Finland. However, UK declared war on Finland on 6 December 1941.