If Japan is neutral, which isn't what this TL is saying, then the RN has ships freed up for the invasion of Norway and for the Battle of the Atlantic. With the increase in ships Norway becomes quite viable. If that happens all of northern Europe is threatened. More lend-lease gets to England which frees up resources to do other things such as increase the pool of pilots for the RAF or to increase the number infantry they have. The US loses less supplies to Europe and does not need as large a navy in the Pacific so they bolster the Atlantic and it doesn't need nearly as large a navy which turn into USAAF and soldiers for the army.