Hitler literally called the Japanese the "honorary aryans" who should be allowed to rule over all of Asia. During WW2, Japan took over all of China, Korea, and Taiwan. Single-handedly. If they hadn't bombed pearl harbor and had actually attacked Soviet Russia, Nazi Germany and Japan would have won WW2.

(http://www.autoadmit.com/thread.php?thread_id=3599811&forum_id=2#33194082)

The Japs did not take over all of China. They got bogged down in a land war in China and were slowly getting bleed to attrition by the Chinese. The first several major battles in the Sino-Japanese war had very skewed casualty rates (something like 6 Chinese soldier for every 1 Jap), but then the tide and casualty rate started turning to something like 3:1 and 2:1. The Japanese lost some major battles in China. The US owed much of the island-hopping successes to the fact that a million Japanese soldiers were tied down in China for a good part of 1937 to 1945.

(http://www.autoadmit.com/thread.php?thread_id=3599811&forum_id=2#33194132)

Taiwan is pretty strong now but they were fucking backwater colonist nobodies in the 40s. They only became relevant after the war because the Chinese Nationalist govt moved there and got US aid to kickstart the economy.

Korea was also completely irrelevant.

China was in a civil war. If the nationalist government was still in complete control at the time, Japan would have had a considerably more difficult time invading.

(http://www.autoadmit.com/thread.php?thread_id=3599811&forum_id=2#33194178)