The reasons for denial of such a well documented and recorded event are complex and difficult to understand. However, it may be because of the course Japan has taken after the war. Nationalism became almost taboo in Japan after the Second World War because it had lead to their involvement in the first place. As a reaction to decades of suppressed nationalist sentiment, the far right nationalists have go so far to claim that Japan has, and can do, no wrong. This means denying any past mistakes such as the massacre.