I tried it in one game and went after Pearl Harbor on Turn 1. I pursued and destroyed the US Navy, but at ridiculous level of losses (my opponent rolled 9 out of 9 dice spot on during the first round of battle)
So no, I have not tried this again, but obviously thinking about it.
The US gains some tactical flexibility (especially in Europe).
If US focuses solely on Europe, I would think Japan can pull out the victory cities before Germany falls.
If US focuses solely on Japan, I’ve looked at how purchases / moves play out, and it seems like Japan is able to use its air force to maintain naval parity by building carriers (see below)
This below assume that Anzac and UK don’t cause too much trouble. Basically, the Japanese air force is worth 222 IPCs, what use are you getting for it if you don’t attack early?
The numbers below show how the board would look like at the beginning of the US turn. Important to watch is the attack value of the third column (Hawai) against the defense value of the first column (Japan). The second column represents the Japanese fleet that should take care of the UK / India, along with transports built Turn 1 and a ground push.
Turn 2 US Turn
Japan JP Other US Hawai US Cal
AC 2 2 1 2
BB 1 1 1 0
Cruis 0 1 2 0
DD 2 2 2 0
Sub 0 2 1 0
FG 5 2 1 4
Tac 2 2 1 0
Value 38 31 23 12
Hits 15 15 11 8
Turn 3 US Turn
Japan JP Other US Hawai US Cal
AC 4 2 3 1
BB 1 1 1 0
Cruis 0 1 2 0
DD 2 2 2 0
Sub 0 2 1 5
FG 7 2 5 1
Tac 4 2 1 1
Value 56 31 35 17
Hits 23 15 19 9
Turn 4 US Turn
Japan JP Other US Hawai US Cal
AC 6 2 4 1
BB 1 1 1 0
Cruis 0 1 2 0
DD 2 2 2 0
Sub 0 2 6 5
FG 9 2 6 1
Tac 6 2 2 1
Value 74 31 52 17
Hits 31 15 28 9
Turn 5 US Turn
Japan JP Other US Hawai US Cal
AC 7 0 5 1
BB 2 0 1 0
Cruis 1 0 2 0
DD 4 0 2 0
Sub 2 0 11 5
FG 10 0 7 1
Tac 7 0 3 1
Value 96 0 69 17
Hits 42 0 37 9