This is a variant of the 4 If By Sea scenario that comes with TripleA. A fifth faction, the Americans, are added to the fray, with their capital on New Zealand.
If you need to be reminded of the rules, or if you've never played 4 If By Sea, here they are:
The same as TripleA except:
neutrals defend themselves
no neutral fee
each non original factory can produce 5 units, but you can have multiple factories in a territory
Enjoy! - adoY Units: infantry armour fighter bomber transport battleship carrier submarine factory aaGun