Basically that. The USA as of today (2018) vs all the armies that participated in both WW1 and WW2.
- No nuclear weapons for anyone.
- Air support is only allowed for the other armies, not USA.
- Battleships are also not allowed.
- WW1 and WW2 armies have perfect teamwork.
- 12 hours prep for USA before the attack (the other armies want to invade USA).
- Other armies will attack from both the south and north borders. USA isn't aware of this. They only know an attack is going to happen.
Who would win?