That treaty was shit.
British and French- "Hur Dur, lets make the nation that invented nationalism pay us more money per year then its current GDP! Duhhhh surely they won't turn into a vengence drivin facist super power cuas we effectivly slaved them to their debt with our puppet government and the massive infrastucture damage the bloodiest war in history caused!"

Hitler-"Need to kill…. rising…."

Wilson was good, but Congress wouldn't cooperate and let him have America do anything. Also all the other countries refused to cooperate either and generally messed shit up as well.

Basically it was everyone's except Wilson's fault, because he was the only one who wasn't being petty and pointed out "hey, maybe we should discuss international concerns reasonably, not force Germany to be broke and bitter, and generally not piss in people's cereal?"

So yeah, it was the world's fault. Treaty of Versailles was godawful and Wilson was the only one who guessed correctly about what would happen. If the Great Depression didn't hit, the non-Wilson route everyone took may have worked since America was keeping Germany afloat and they could have healed without as much radicalization resulting from everything being shit.

FDR came to office after everything had already went to shit and Hitler came to power the same year. It was too late to really stop WWII by the time FDR was around.