If the US is building offensive fleet THAT heavilly, then they REALLY have nothing heading to Europe. Between the Med Fleet and the Baltic Fleet and the Luftwaffe, GERMANY has a pretty good chance to take control of the Altantic.
Also, Japan can build up right along with the US on the Naval front, and STILL send units to Asia. Japan will have built 1 IC in Asia before the US even makes their first move, and built up a respectable TRN fleet of 3 TRNs off Japan. That allows for 9 divisions per turn into Asia, more than Russia’s entire national produciton.
After J1, The US has 3 ships in the Pacific, and 3 in the Atlantic. To get a fleet to the specifications you state above Jen, the US would ahve to send EVERY existing ship they have to the Pacific, use all of their existing FIGs for their carriers, and STILL spend $154 IPC’s to build up the remaining ships and the 4th FIG.
That is 4 turns of NOTHING but naval units.
Nothing to fill the TRNs
No Bombers to UK to Bomb Germany
And it also assumes you did not counter-attack Pearl so taht those American ships and planes stayed alive for your build up, otherwise add 1-2 MORE turns to the time needed to build that fleet.
So Jen, I have NO CLUE where you come off saying you can get a 200+ IPC fleet in 2 or 3 turns. You need a minimum of 4 turns, and that is buying NOTHING but the ships.
Now, while the US is building that fleet, Japan is sending units to Asia, and building up their fleet.
While supporting landings to Asia (up to 9 divisions, 3 prodiced on the mainland and up to 6 trannied in from Japan)
Japan can still produce 1-2 naval units per turn, depending on income and the number of forces they want to ship to Asia
Starting Units as of end of J1:
2 BB
2 AC
4 FIGs
3 TRN
Possibly 1 DST, depending on Pearl J1 results.
In 4 turns, by the time the US gets the fleet you specified, Japan adds:
1 AC
2 FIGs (existing land based units moved to third AC)
1 DST
2 SUB
And that is just ONE ship a round. Japan could always reduce the Asia landings and build more in any given round.
On the final round before the US strikes, Japan goes full bore on navy, buying 4 SUBs and leaving the work in Asia to the units already shipped in (though by now, Japans income is well elevated, and they can still produce a few INF at their mainland IC even this round).
Now, on US6, the US fleet can attack.
US: 1 BB, 2 AC, 4 FIG, 2 DST, 4 FIG, 12 TRN
Japan: 2 BB, 3 AC, 6 FIG, 2 DST, 6 SUBs, 3 TRN
The US has a whopping 3% chance to win that fight. And Japan only lost ONE ROUND of sending units to Asia.
So let’s say the US does NOT attack, but goes Island Hoping instead since they cannot crack the Jap Fleet.
They get an island, only 1 since the US can;t split their fleet or risk destruction.
Japan builds 4 more SUBs then attacks the US fleet the following round, adding a land based Bomber to their fleet.
70% destruction of US fleet in J7.
And again, taht was with Japan only building ONE SHIP per round while the US spent EVERYTHING on Pacific Navy.
So, after the 4 turn US build up to get their fleet, they move toward Japan, and get halfway there in T5.