The depth of historical ignorance under which they labor is so great that the question defies honest response. The war in Europe was over months before the first bomb was ready, and indeed we bombed the living shit out of the German rail network, every railyard bigger than a siding had been bombed (and continued to be bombed as soon as it was repaired) and despite superhuman efforts to keep the trains running, at least 10% of even the cross-country trackage was unusable on any given day by the end.
The idea that bombing cities was a war crime is strictly a post-war one, and exists thanks to our ability to use PGMs to take out more-defined targets. In WWII, there were several military and practical reasons why we bombed entire cities (dealing with both the limitations of the available ordnance and its delivery systems, as well as the decentralization of manufacturing into piecework in home workshops in Japan, and the idea that the civilian housing was where the off-shift factory workers could be most readily killed in the case of Germany), unsavory as it is may be by modern standards WHICH DID NOT APPLY THEN. Even more importantly, though, both the Japanese and the Germans bought a ticket on that Hell-train when they were on the offensive in the first two years of the War, and clearly had no reservations about mercilessly bombing civilian populations to the limit of their capabilities when the ass-kicking boot was on the other foot.