That is has never been resolved.
Largely those that say it is do so on account of the already ongoing genocide that the Japanese were committing on other nations and that the Japanese refused surrender despite warnings and then again after the first bomb dropped.
Those that say it isn't do so on account of the number of civilian deaths, general immorality and that it was excessive in its nature.
Personally, I would consider the first legal as per "jus in bello" and the second a war crime as the impact of the first probably hadn't been fully comprehended at the time the second was dropped.
Chat with our AI personalities
The Diet
Israel launched the first attack of bombing Egypt's Airforce, but Egypt provided a prior causus belli by blocking the Straits of Tiran (an illegal act according to international law).
ships of neutral nations were not to be harmed
the war powers act
The US Military was segregated until Truman signed a new law in 1947. Two years after WW2 ended.