Which of the neutral nations could have made the most decisive differences in WWII had they instead picked a side to fight for?

by [deleted]
Bernardito

Unfortunately, this question does not have a place in this subreddit since it can only be answered through speculation.

Domini_canes

From the rules:

Questions should be about what did happen, not what could have happened. Questions of that type should be posted in r/HistoricalWhatIf.

You may have much better luck over there.

(Note: I am not a moderator)