A nonsensical false dichotomy of sorts. Between "Japan surrenders without a single further death" and "We have to nuke two cities for them to surrender" there are numerous steps of gradual escalation that could have been taken before arriving at the "nuke the cities" option. One such possible step could have been nuking a remote area, or at the very least sparsely populated area, to achieve the demonstration of destruction without hundreds of thousands of deaths.

I have no sympathy for the Japanese who killed tens of millions of people in their WW2 atrocities, and the two bombs killed orders of magnitude fewer of their people. I also see no reason to pretend that there weren't obvious alternatives to USA dropping nukes on their cities if we are to believe that the objective was merely getting Japan to surrender (an objective most difficult to believe). No need for pretense -- they wanted to demonstrate their new weapons, AND they wanted to kill a lot of Japanese.