Posted.
Excuse me for being late, I was really planning to do this on Friday night.
Worse, I even rushed a bit with this one, though everything that matters are already in it.

Yes, the fourth battlefield is New York or at least a 1000x1000m section of it.
I leave it to the GM to decide where this part is.
The streets are practically empty but otherwise everything else is operational.
Also I imagined that if you reach the end of the battlefield then you are transported to the other end of the map.