Yes, I have played a few well known players on this site that all seem to be making the same mistake, they are investing in the Atlantic with the United States of America and thus, are having a bit more trouble in clearing Japan out.
Don’t get me wrong, they do eventually clear Japan out, they just have a much harder time of it than if they go whole hog after Japan. If the United States ignores the Atlantic for the first 6 rounds of play, Japan is done for. If they are more conservative, they can easily ignore the Atlantic for the first 8 rounds of play and really drive the nails into Japan. Again, all you need to do is bottle Japan up and that is no where near as hard as actually beating Japan.
Once you are too strong to beat (defined: If Japan throws it all at you, they lose and you win) all it really takes is an investment of 30-40 IPC a round to maintain your power. The other 40 IPC a round can go into the Atlantic and CRD the Europeans / Liberate England (Africa should not be lost. Unless the attack on SZ 97 went REALLY badly, Africa should be just about to capitulate to the Italians by about round 8.)