Uhhh, I think the world knew a lot more about Hitler in 1939, than they did in 1934, don'cha think?
How much did Poland know about Hitler in 1938 when it joined Germany in invading Czechoslovakia?
I guess they found out later when Ribbentrop demanded Danzig as the price for continued 'nonaggression'.
Graj w głupie gry, wygrywaj głupie nagrody