In the European theatre, we had the ability to fire bomb cities and civilian casualties weren’t counted. When Germany surrendered, there weren’t too many buildings still standing in any of their cities. If we used those rules of engagement, Iraq would be nothing more than a sandy field of ruins and the war would have ended six months or earlier after we went in.
Much of that was not due to the strategic bombing. Rather they were the result of the taking of those cities by the allied armies. This was especially true in the East, which included Berlin.
Although the Brits did bomb cities indiscriminately, the USAAF used precision bombing, such as it was, to hit only targets of military importance, but that did include factories and infrastructure, so those strikes also killed lots of civilians.
OTOH, Curis LeMay firebombed Japanese cities, with the intention of killing all the workers and their families, who lived in those paper cities. He killed more in a single night of firebombing Tokyo than were killed at either Hiroshima or Nagasaki. But he didn't limit himself to a single night of bombing Tokyo.