The war in Asia and the Pacific was a clash of armies, a clash of cultures, and – most brutally – a clash of races. Race war was the way the conflict was understood on both sides, that was the way it was fought, and the POWs suffered for it.
     There were white men, and yellow men that had life-and-death power over them. The Japanese had a formal warrior code, bushido, that taught soldierly correctness and right attitudes to duty in the warrior’s life and the warrior’s death. But anything touching upon respect for the enemy, or mercy, or restraint, did not carry over into the POW camps of World War II. In the eyes of the Japanese, white men who allowed themselves to be captured in war were despicable. They deserved to die.
     The Japanese did not directly use genocide in their POW camps. They did not herd the white prisoners into gas chambers and burn their corpses in ovens. But they drove them toward mass death just the same. They beat them until they fell, then beat them for falling, beat them until they bled, them beat them for bleeding. They denied them medical treatment. They starved them. When they received food and medicine from the Red Cross, the Japanese looted the shipments. They watched them die by the tens of thousands from diseases of malnutrition like beriberi, pellagra, and scurvy, and from epidemic tropical diseases:  malaria, dysentery, tropical ulcers, cholera. Those who survived could only look ahead to being worked to death. If the war had lasted another year, there would not have been a POW left alive.
     Source:  Prisoners of the Japanese – POWs of World War II in the Pacific, by Gavan Daws, p 17-18.

There were reasons for this conflict of culture as stated by Van Waterford in his book Prisoners of the Japanese in World War II.

•  Economic conditions due to the strangulation of the Japanese by the West after the U.S. announced its 1942 oil embargo, and because of the controversial landing of the Japanese at Cam Ranh Bay and subsequent occupation of Saigon and Danang; this action taken against Japan by the West left the Japanese resentful of American authority.

•  Stereotyping and racist thinking by the west; the Americans has a long history of segregation and poor treatment of the Japanese migrants and citizens in the United States.

•  Continued colonization by the West as it sought occupational control of the many smaller islands in the South Pacific.

•  The Yamato tribe that unified Japan through the common belief in the superiority of the Japanese people over other cultures, especially Western cultures.

•  The existing cult of Bushido, the warrior who believed in honor, obedience, and valor and sincerely believed in the emperor’s divinity and that dying for him was glorious.

•  The individualism of the Japanese soldier within the framework of group actions, causing commanders in the field to frequently disregard orders from the Tokyo War Ministry, and in the belief that they were acting in the emperor’s best interest.

•  The dishonor of being captured, or horyo – a dishonored captive – led many guards and camp leaders to be insensitive to their American prisoners who so easily surrendered; the Japanese culture accepted death before dishonor and to surrender was dishonorable.

•  The insularity of the Japanese soldier; for years Japan had been isolated from the West; isolation from other cultures was the catalyst for their belief that the Japanese were superior.

•  The emotionality of the Japanese soldier; always trying to “save face” and keeping up appearances.

•  The tough training of the Japanese soldier; he was trained to believe that loyalty, in all its sacrificial manifestations, was the greatest expression of military spirit. Inflexible duty was its corollary, with a fatalistic bind to a life of service. The Japanese soldier’s own outstanding military behavior, even in a life-and-death situation, would be publicized only briefly while he was alive. Lavish praise and great honors came after death. This twofold policy prevented the creation of national heroes, while further underlining the glory of death on the battlefield. Furthermore, the relatives of a captured Japanese soldier were never notified. If they suspected that he was imprisoned, they were obliged to show that he had brought everlasting dishonor to his family and himself, and that it would be better if he were dead for he was marked as a traitor to the imperial cause.

Van Waterford, Prisoners of the Japanese in World War II, page 15-23.

Colonel Irvin Alexander, Surviving Bataan and Beyond, Colonel Irvin Alexander’s Odyssey as a Japanese Prisoner of War, Stackpole Books, Mechanicsburg, PA, pp. 252-253.