I had a radical Iranian foreign policy professor of all things, who said we dropped the bomb on Japan because we wanted to use it on “yellow people” and not white Europeans.
I knew and told him we built the bomb in a race with Germany to develop it before they could, and use it against them, but the war in Europe ended before the bomb was ready. He scoffed at that.
I haven't had anyone pull that on me since that time in the '80s, but the next time, in addition to my standard reply, I'm going to ask if they thought that the Japs would refuse to use it on white people because it might be construed as racist. Then wait for the deer-in-the-headlights look.