I’ve had to face this and it is a pain. But there are options for the US.
First off the attack on Pearl is only 62% for Japan to win, and even if they win they should only have a handful of units left, like 1 or 2, 3 at the most. If they fail to take pearl you can hide your fleet in SZ2 while blocking SZ 25 with a destroyer, this means Japan fails to take Pearl till turn 3, by which time US should have naval parity.
If the attack succeeds you have a problem with the US, because 6 planes can hit along with the remaining units. If you leave your fleet there the Jap will sink it and soak most of the hits with capital ships, then retreat to Pearl. The first thing you have to do is see if you need more ground units to keep WUS safe. If you don’t need any more, then that is awesome, you purchase an airbase and put it on the johnston island, move all your boats except a DD (to block bombard) down there along with your planes. Even the fig from phil can make it to the carrier. Then ANZAC can land all 4 of her figs on the island as well. At that point the IJN would have to defeat a naval force of: 7 figs, 2 tacs, 1 BB, 1 Cru, 1 AC, and 1 SS. It is a fight they can win, but they will not have much left afterwords and on US3 you drop a huge navy. You could also use the island Samoa. On following US turns you can either build up a huge airforce, simply save for a turn to drop a massive navy and send your boats in the DEI area, or whatever you wish.
Now for the trick where Japan stacks Pearl with fighters. Simply send your fleet to Midway once it is large enough, then Japan is forced to defend 2 key islands.
But, the big thing is, if you scramble a tac to negate the shore bombard at Pearl, it is a 62% chance for them to win, if they do win you still have a good chance to win the game! If they loose then it will cost them the game.
@Uncle Joe: The really funny thing about this map is this. If Japan controls all of asia and the Philippine islands they make 55 IPC a turn, same as the US. This is why DEI is the absolutely most important area in the game. It is the economic decision maker on who has the advantage.