The Nukes on Hiroshima and Nagasaki will ALWAYS be controversial as they were the first (and hopefully only) time nukes directly targeted and deployed on people.

There's a lot of debate if they were required since the Soviet Union push starting against them would probably mean they'd prefer to surrender against America to preserve their culture than have communists on Japanese soil. Maybe but there was internal communications in the higher Japanese government that rejected any surrender since the US wanted unconditional and it was only after Nagasaki that they thought the US had HUNDREDS of nukes to drop did they think to just surrender.

Hell they actual tried to coup the Emperor as he was surrendering so that was the level of resistance to it. They were so indoctrinated into the cult of the Emperor that a single photo of him standing next to a US General shattered a lot of that seeing how small he was in comparison