What you build in response to a J1 attack largely depends on what the Japanese have where. If they are mostly down in PI and DEI, then the US has a little breathing space. Of course with only 17 IPCs on US1 it’s not really that relevent what you buy IMO. I’d probably go with the CV or 2 DDs, After that, you’ll definitely need TRs. Without them, the Japanese dont have to come out to play. They can just sit back in a mass and create the stand-off that results in an Allied loss.
For ANZAC, I’d prolly go with a TR or a plane if the Japanese are near Australia.
For the Brits? Yeah, prolly more Infantry. If the Japanese are massed at PI or the Carolines, maybe a Sub or a TR depending. Again, the TR is necessary to provoke a Japanese response. If it will survive the turn and be able to land on an island in the DEI, it’s an investment worth making if for no other reason than it will annoy the Japanese. ;)
If you look at the above, you’ll likely have 2-3 TRs quickly in striking position to something of interest to the Japanese. Sure, they can stomp out any of those threats but they’ll have a harder time stomping out ALL of those threats. And that’s where the harassment begins. After that, the US can start to turn up the pressure a bit more with TRs and escorts (DDs and maybe a CA for shelling outpost defenders). A nice safe ‘normal’ US outlay might be 2 DDs, 2 SSs, 1 CA, 1 TR, 1 Inf, 1 Art for 54 IPCs. That gives you some good hitting power and some good diversity as well. If you need to picket, invade, hit convoys, or fight a minor engagement you have the tools with that build. And it keeps the Japanese guessing. If they come at you with full force, use the ANZACS and Brits to raid and wear them down by attrition.
The overriding issue is that Japan is on a tight timetable after a J1 attack. The US is immediately making 55 and the Chinese and Brits are still in the game. The Japanese econ is likely less than half of the combined Allies for the first turn or so. Japan will be feeling the pressure to crank her income and that early in the game she will still need to be building TRs and ground troops, diluting what she can build to augment the fleet. She can’t be everywhere and you know the places where she wants to be (likely the DEI and PI and then supporting operations against the Brits). Force Japan to guard each of the islands and that will quickly run her out of ground forces for the mainland and/or TRs. In the end, the game will likely be decided in the first 4-5 turn after a J1 attack. If Japan succeeds in holding things together and has her econ roughly on par with the surviving Allies, she’ll win. If not, by turn 5 the Japanese will likely be strained to the breaking point.