Logistically it's very clear that the US had an advantage but it should be noted that wars are not won by logistics alone. They're won by who kills more people or who reaches the capital. This is what really makes the Russian perseverance so amazing. They lost 20 plus million and didn't give up. In the Pacific theater though we lost about 160,000 soldiers. Japan lost over 100,000 in just one night of firebombing on Tokyo. The real question really is if Japan could ever have inflicted mass American casualties. There was little chance of them reaching our capital and forcing a capitulation. It wasn't even part of their plan. However if they had wiped out Hawaii and killed 100,000 soldiers in the beginning of the war things could have ended much faster - and not in our favor.