it isnt modeled in the game, but it seems to me the partisan problem would be made much worse by the spectacle of foreign troops firing on american citizens on american soil. Hessians, as it were.
Also, is it true with nukes that if you nuke a national province of a nation that previously nuked you, don't you lose the original nuke dealt you?
Common dude you're the USA!!
Dont let your guys down man! look at alexander, his country fights now on the German side and hes still on your Side!
Again, what happens if Mexico, Panama and these countries joins you? the Argentina empire is from Tierra del Fuego to Brasil or what?
From there, you could deal with the south american axis while nuking europe, as was said?
One advice: Give to Spain a province with VP far away of the hands of the Axis, because if Spain is annexed, you will lost all the spanish divisions.