I prefer to wait until J4 to attack USA.
I put a Naval Base in Formosa so that I can force India-UK to reconsider supporting Africa with fighters.
Naval Base allows me to travel to Caroline Islands at the end of J3 for potential attacks on Anzac or Hawaii. It also forces India-UK to play a blocker between India and SZ36 or face transports loaded with infantry confronting Calcutta on J3/J4. I WANT this to happen because I’m moving J3 to Caroline Islands with my fleet and any purchases at defending Calcutta are another turn India-UK isn’t trying to take Yunnan.
I don’t let US enter the war until the absolute last second as I need the IPC bonus for Japan collecting those 30 IPC over the 3 rounds.
I crush Hawaii on J4 with the full contingent of my fleet and doing my best to take Hawaii. J4 I usually buy as many destroyers as I can get because the typical US move if they lost Hawaii is to buy as many subs as possible and chase my fleet out of there. Being able to reinforce them with 4+ destroyers makes it daunting to try to retake with a sub purchase on US4.
I go straight after China and ignore Russia(Russia’s first move should really be to attack Japan and stop the push in China. Their loss is only 12 IPC of units that really don’t do much unless Japan has already taken the Burma Road and held it.). I don’t stop attacking and am willing to lose fighters to take Burma on J4. J5 is too long to try to take Burma, but you’re playing the delay tactic of keeping UK out of Yunnan as long as possible.
If USA isn’t focused on a full Pacific purchase on US3 from a potential assault on Eastern US, I keep the pressure on from Japan on J4 and move after Western US. Losses aside, the USA has to choose which side to defend and one side’s doing to lose. With DC in the East and getting the heavier defense, it makes sense for Japan to all out attack the West after taking Hawaii. If US goes full Pacific, I sit tight in Hawaii for 2-3 turns, trying to reinforce Hawaii with transports and infantry. Holding Hawaii and forcing US purchases aimed at re-taking Hawaii buy even more time for Germany to handle the UK/Russia in Europe. Each turn the US isn’t threatening a European invasion is another turn the Axis are winning. Especially if G4 doesn’t actually attack Eastern US and continues with Sealion from SZ91 a turn later and with an Italian softening of UK forces in SZ109.