But when we, or Huntington, are talking about the ferocity, ruthlessness, bloodiness, and intractability of wars along cultural fault lines, we're not talking either politics or economics, but the way people look at each other, across cultures. And neither we nor they, at the bleeding edge, saw the other as quite human, and worthy of human consideration. And there, in both cause and effect, Huntington's model suits the Pacific War to a T.
But Huntington's model doesn't apply to how cultures and values can change across time or within institutions. Witness the enormous variance in military institutional culture in the Imperial Japanese Army between, for instance, the Russo-Japanese War and the Pacific War. The Japanese took enormous casualties in both wars, but the treatment of POWs taken by the IJA was almost completely reversed.

Also the treatment of Chinese civilians during the Boxer Rebellion (notably good, especially in comparison to the Western forces they fought alongside) by Japanese forces in 1900 versus the Japanese invasion post-1932 (perhaps exceeded only by the Germans in Eastern Europe) is also an example of how institutional culture can radically change in a very short amount of time.