He saw close up how the Japanese were fighting. he was always deadly serious when he told me as a kid that I would not have been born if the bombs had not been dropped.
You will not find a Pacific War vet that ever thought the nuclear strikes were inhumane or unnecessary. That is purely an invention of latter day leftists.
My great grandfather, who helped raise me, always told us kids that he would not have come home if they had not dropped the bomb. He was on a Navy warship and watched kamikaze pilots attack other ships. I will pass on that fact to my children, grandchildren, etc...