The argument that if the US has used nukes then it's ok for everyone else to have them, is the kind of logic that I can't wrap my head around. This is not even factoring how different the moral landscape was at the time compared to what it is today. There's plenty of literature available on why the atomic bombs on Japan was at the time perfectly necessary for ending a war that Japan never intended to withdraw from. An invasion of Japan would ultimately have led to far more causalities. Nemesis by Max Hastings is probably the best book on the topic IMO. Read it and you will also learn how Japan to this day is whitewashing its own horrific atrocities in China.
Heck, the Allied firebombings of Dresden and Hannover caused more civilian casualties than the nukes but no one ever picks those as an argument to ban conventional bombs.
Heck, the Allied firebombings of Dresden and Hannover caused more civilian casualties than the nukes but no one ever picks those as an argument to ban conventional bombs.