By May 1942, Japan had overrun Malaya, Burma, the Dutch East Indies, and the Philippines. These easy victories seems to have warped the judgement of its rulers, for Japan continued to occupy territories across the South Pacific, ignoring the fact that it could not hope to defend all its gains at once. The drawn Battle of the Coral Sea on 7/8 May dented the myth of Japanese naval invincibility and the Battle of Midway on 4/6 June completely shattered it (both battles were fought between the Japanese and American navies). Afterwards, Japan still had some local successes, but its rising sun was now past its zenith. Nowhere was this clearer than in Papua and New Guinea (both administered by Australia), where the Japanese, deprived of air superiority and unable to feed from captured supplies, lost their reputation as jungle supermen.
The jungles of Burma also added to the myth of the Japanese soldier being “at one” with his surroundings and following the almost disastrous first Chindit expedition where the casualty rate was quite horrendous, mainly as a result of the various jungle maladies such as malaria, beriberi, dysentery and a host of other illnesses, many lessons were learned. The second Chindit expedition was much better prepared with much training given to the arts of jungle warfare and survival, and following Mountbatten being assigned to the post of Supreme Allied Commander (Far East) much use was made of the allied airborne support capabilities in flying in air dropped supplies using DC3 "Dakotas" and flying out of casualties from makeshift airstrips in jungle clearings. Quinine also played a major part in combating the scourge of jungle warfare; malaria. With the successes of the Chindits and to be fair to our American allies, “Merrill’s Marauders”, the myth of the Japanese invincibility in the jungle was well and truly laid to rest.