There is a certain leap between "civilian casualties are unavoidable" and "a civilization Is going to be destroyed and sent back to the stone age through war crimes"
Trump's comments are quite obviously saber-rattling. Until now at least, the U.S. hasn't executed 30,000+ Iranians in a short period of time, and countless more over the past five decades.
Regime change isn't the real goal here, is it? Haven't followed closely, but to me it seems the goal is to just destroy Iran as a regional power, with dire consequences for its population.