Japan became a sick culture because the power elite has so thoroughly rejected Christianity. At the time of the atomic bombing, Nagasaki had the highest concentration of Christians in Japan. The city's Christians held out resolutely for centuries against pagan oppression and persecution that would have forced them to deny Christ. Some Christian Japanese will tell you that it was the slaughter of innocense that stopped the war as it's martyr's blood that shares both fate and Glory in Jesus' Perfect Sacrafice that paid for all mankind's sin.
I'm not really one to get involved in religious claims but a little bit of Christian humanity was exactly what I was thinking. If you'll excuse the psycho-babble, the culture of death that the Japanese had could not make a person truly happy in my opinion.