YANBU.
My (Irish) dad served in the RAF and had a German sister in law, and had no qualms whatsoever about the bombing of Dresden, or Hamburg, or any other German civilian targets, having seen the destruction of British cities and having no doubt as to the fate of Ireland and the Irish if the Nazis had ever got that far. Just as attacks on civilian centres in Britain were intended to terrorise and reduce confidence in the British government and armed forces, the attack on Dresden had the aim of destroying confidence in the Nazi government and armed forces.
Operation Barbarossa was the granddaddy of all war crimes. How many Soviet civilians perished? How many Soviet POWs were starved or frozen to death, deliberately, while in German hands?
As to 'never another incident like it' -- there had already been plenty of incidents like it, including an aerial attack on Stalingrad, a city full of civilians, on 23 August 1942, followed by a systematic block by block destruction of the city by the 6th Army that went on for five days.
Warsaw was to be razed in 1944 as an example to any other cities. Between the ravages of war since 1939 and the deliberate plan of 1944, and after being looted, almost 90% of the city ended up systematically destroyed, in full knowledge that the armies in the east were doomed, and that better use could be made of forces tied up in the rampage of destruction. Over half a million of the remaining citizens were rounded up and sent to various horrible fates in different camps. This was after the Jews of the Warsaw Ghetto had been wiped off the face of the earth. Paintings from hundreds of years before the 20th century had to be used to aid reconstruction.
'The city must completely disappear from the surface of the earth and serve only as a transport station for the Wehrmacht. No stone can remain standing. Every building must be razed to its foundation.'
—SS chief Heinrich Himmler, 17 October 1944
Even before the invasion of Poland, plans were hatched to turn Warsaw into a German provincial town of about 150,000 population.
The use of the Dirlewanger Brigade in the USSR and Poland, led by the sadistic psychopath Oskar Dirlewanger, ranks among the most heinous examples of terror inflicted on a civil population in history. His unit is held responsible for the massacre of at least 100,000 citizens of Warsaw alone during the closing stages of the war. The unit became so notorious in what is now Belarus that even some SS officers wanted to boot him out of the SS and away from their field of operations.
Kharkov, a city of almost 1 million, with its population swollen to over 1.5 million including refugees ahead of the German advance, finished the war with a population of 190,000.
Atrocities committed in and around Rostov were well documented.
The city of Leningrad, full of civilians was besieged from 8 September 1941 until 27 January 1944, two and a half years of horror that featured bombardment, disease and starvation.
And this and much, much more is on top of the Holocaust. The German war aims in the east included extermination of the civilian populations.
Too bad Dresden got bombed into smithereens. A little perspective is in order.
If you can't take it, don't dish it.