Coming down from the skies to the seas, FDR also traded 50 "old" U.S. destroyers to Britain in 1940 for basing rights in various British possessions, a move which critics decried as a violation of the Neutrality Acts. What isn't well known is that the Brits took these desperately needed warships and immediately began refitting them, in part to make the officer's quarters larger and the crew's quarters smaller, a very British thing to do. (WW2 histories I've read are silent on this, I heard it from a WWII Navy veteran who saw that first hand.)
So we had our hands - to some degree, anyway - involved in WW2 prior to PH.
Argentina did too . . . but sorta kinda on the other side, considering how many Nazis ended up settling there. They probably didn't particularly like NortAmericano Gringos.