[1.0.1][e05f] Japan declared war on USA

[oerbaa]

Japan, before even joining the axis, declared war on the US. This is with historical AI turned on.
The war in Europe just started, Germany didn't even push far into Poland yet. I was playing Italy, see SS below.

 

[King-Salomon]

would guess the "problem" was the tension Italy produced by annexing Yougoslavia...
if you rise the tension too quick too early you can't expect the outcome to be "historical".. the "historical important focuses" will trigger much faster

 

[Riktol]

I think this is a strategic AI bug, they are deeply engaged in china in the screenshot, surely starting another war should be a low priority until the current war is complete?
I have seen them declare war on the US when they have been practically driven off the Asian mainland (naval invasions into southern China driven back, nearly pushed to the tip of the Korean peninsula and being driven back in British Raj) so the AI is clearly not taking the current situation into account.