It was amazing how quickly Japan was able to expand and how quickly we put them on their heels. By the end of 1942, we knew Japan was going to lose the war. We didn’t know that in Europe until mid-1943 when we invaded Sicily.
The Japanese really liked modern weapons, but they had an imperfect grasp of modern tactics and strategy. They had a relative cakewalk during their Pacific expansion, with just a lot of diplomatic incidents as a consequence, until they decided to attack a country geographically isolated from themselves (and from Germany for that matter), that also had an economy about five times larger than that of Japan. Even with the US going after Japanese shipping, the Japanese economy grew some during the war, but the US had an economy eight times larger by 1945.
Plus, we'd completely kicked their asses on land, sea, and air for over three years. :^) :^D