Why did the Japanese not defend the beaches, and instead dig in to caves in the highlands?

The Japanese did not defend the beaches, and instead dug into caves in the highlands to nullify to American superior air and sea power. Towards the end of the May monsoon season, roads were destroyed and flooded, and there was a lot of mud.

Explanation:

This battle was significant in terms of naval warfare because it was the first fleet in which aircraft carriers engaged each other. Neither side's ships sighted or fired upon the other.

Battle of Midway

This battle was a tactical victory for Japan yet a strategic victory for the Allies as ships sunk, but strategic victory as Japanese expansion had been turned back, and Japanese fleet carriers were unable to participate in a battle a month later, called the Battle of Midway which contributes to the US's success in that battle. Dates: May 4, 1942 - May 8, 1942

Battle of Leyte Gulf

This battle occurred one month after the Battle of Coral Sea - June 4, 1942. Japan lost 6 destroyers, carriers, and planes, and the Us lost 2. The US ultimately won by using a high altitude bomb attack after they lowered the Japanese to a lower altitude. This was a critical battle as the US had finally stopped Japanese forces.

Battle of Iwo Jima

26,000 Americans and 22,000 Japanese were killed. One American soldier described the Japanese as "not on Iwo Jima, but in it" because the Japanese fortified it with underground tunnels so that they could move around unseen to their trenches.

Battle of Okinawa

12,000 Americans killed, 38,000 wounded. The Japanese did not defend the beaches, and instead dug into caves in the highlands to nullify to American superior air and sea power. Towards the end of the May monsoon season, roads were destroyed and flooded, and there was a lot of mud. Instead of being killed by Americans, many Japanese died towards the end of the Battle of Okinawa by being injected with morphine or just left to die.

The Japanese did not defend the beaches, and instead dug into caves in the highlands to nullify to American superior air and sea power. Towards the end of the May monsoon season, roads were destroyed and flooded, and there was a lot of mud.