A lot of this depends on the UK. If Germany pulls off a successful Sealion, then the US should spend primarily in the Atlantic so they can liberate England. You don’t want to totally ignore the Pacific, but just spend enough there to keep Japan from going wild all over the Pacific. With good strategy and some luck, a smaller US presence, ANZAC and India should be able to keep Japan busy long enough for the US to get England back in the game before Italy and Germany get too strong.
However, if Sealion fails or is not attempted, and the UK stays in the game for a while, then I would say US should spend primarily in the Pacific. Again, you don’t want to completely ignore the Atlantic. Perhaps a few destroyers to hamper German sub activity, some troops to help take back/keep Gibralter, maybe even a small invasion force on Normandy that can be backed up by British troops and open the way to liberate France. With a small US presence, the Brits should be able to keep Italy in check in Africa and the Med while also harrassing the Germans enough so the Russians can better keep them from taking too much of Russian territory. Meanwhile, a much larger US presence in the Pacific can pound the Japanese navy out of existence while steadily driving them back to Japan. The US should be able to replace it’s naval losses better than Japan, especially since Japan will also have to support the land offensive against China and India. Japan will keep losing valuable units while the Allies grow stronger.
