The event that officially caused the U.S. to enter World War II was

Germany's invasion of Poland
Germany's sinking of ships with U.S. passengers
Germany's bombing of London
Japan's attack on Pearl Harbor

Question

The event that officially caused the U.S. to enter World War II was

Germany's invasion of Poland
Germany's sinking of ships with U.S. passengers
Germany's bombing of London
Japan's attack on Pearl Harbor

solomonzelman · Answer

at first US was isolationist, but when they got .... they intervened.

solomonzelman · Answer

Don't want to give out answers directly.

kyanthedoodle · Answer

So it would be B then, right?

solomonzelman · Answer

No.

kyanthedoodle · Answer

Oh...Oh! It's Pearl Harbor isn't it?

solomonzelman · Answer

yes

solomonzelman · Answer

That was officially the why

kyanthedoodle · Answer

Ok I was confused at first, but now I get it.

solomonzelman · Answer

They were exporting Guns to GB before, but they didn't directly fight (not until the Harbor).

solomonzelman · Answer

and btw, that was Japan's worse move (to attack US).

solomonzelman · Answer

I mean not GUns to GB, rather aircraft also

solomonzelman · Answer

anyway...

kyanthedoodle · Answer

Well thanks