If Japanese war films are snubbed in the West, if they have been consistently ignored when they were not quasiromanticized mythic affairs like RAN, that's not done on any political grounds. After all, the Japanese are not only the first to condemn the rigid militarism that brought them to the brink of complete destruction in WWII but the only ones to offer that condemnation against Emperor and Generals in such a scathing manner. If you won't find films like this or THE BATTLE OF OKINAWA mentioned in the same lists as their disillusioned American Vietnam-war counterparts like APOCALYPSE NOW, it has to do with the same cultural reasons that keep Japanese (or French and Italian) crime films in the shadow while Scorsese, Tarantino and their cohorts reap all the glory.
And even when the spotlight falls on the individual rather than the collective, the lowly Japanese soldier haphazardly trained in a few weeks time and sent with meager provisions to conquer New Guinea, the Philippines, or Indonesia in the name of the 'Motherland', the focus is not on a heroic celebration of courage and valor because these men where not heroes and what courage they showed in the face of death was instilled in them by the fear of worse things like malaria and malnutrition or even worse, the fear of their superiors executing them for cowardice, but rather on grim endurance beyond all hope and glory with nothing else to look forward to but returning home to a ruined country and American occupation. The chaos squalor and misery of postwar Japan Kinji Fukasaku knows firsthand. It's the place and time he grew up in and the memory of that misery would resurface regularly in his work as a bleak backdrop to the yakuza films through which he became known and for which he never received the acclaim he deserved.
This is the greatest success of UNDER THE FLAG OF THE RISING SUN. Not the narrative maze of the script (written by Kaneto Shindo of ONIBABA and KURONEKO fame no less) carrying echoes of RASHOMON and CITIZEN KANE that shows the wife of an executed soldier trying to piece together the life and death of her husband in WWII New Guinea through the conflicting memories of his surviving comrades and superiors. It's the hopelessness and despair of men trying to survive like savage beasts in a hostile jungle, the memory of that despair relived in and contrasted against a booming 1960's Tokyo by the miserable survivors, that visceral gutpunching quality of man's tragic struggle for survival in a world that bears him false witness, for which there is no glory to be had which, sets apart films like this and Kon Ichikawa's FIRES IN THE PLAIN from their American counterparts. Major battle scenes and historic events are in the background, presented in Fukasaku's trademark quick montages using stock photos. Like the best of Southern literature, the Japanese war film is fueled by the memory of defeat, by loss and pain and destruction. If it sometimes seems exceedingly grotesque, it's only because it's realistic.