We no more knew on 12 Feb.45 that "the war was over", than we knew on 5 August 1945 that Japan was "ready to surrender". Armistice, maybe...back to 1938 borders, recoil, the better to spring... but Unconditional Surrender, Occupation, subjugation to the barbarian...oh, no. Remember Churchill's June 1940 words about (MPs and all) Brits choking on their blood as they fought the invader...remember "better dead than Red": Germans and Japanese civilians loved their Homeland just as we did/do. For them, all of their enemies, not just the Eastern one, were bad guys. They would fight on to the last kitchen knife until their own blood nourished the Motherland.
Demonising Dresden, carpet bombing generally is untutored (esp. by the Philosophy tutor Prof. A.C.Grayling, whose Down Among the Dead Cities, in every UK Public Library, holds Bomber Command aircrew to be collective war criminals). The most effective way to reduce a castle under siege was not to clamber up its defended walls, but to poison the well and interdict resupply; the purpose of Henry VIII's Royal Navy was to bombard ports and interdict resupply: both bring Weapons of Mass Destruction onto the civilian population. Get the job done, so our boys can come home. It was civilian starvation of the Central Powers caused by Allied Naval blockade that was seen by our Leaders as having won WW1. Blockade/interdiction of supply, this time maritime+aerial, was the strategy adopted by UK in 1937 (KGV battleships and (to be) Stirling/Halifax/Lancaster), adopted in 1941 by US' Two-Ocean Navy and Ford Liberators en masse, and by (less effective) Russian, Italian and German attempts at Heavies.
"Carpet bombing" created no new "frightfulness": just that by 1944 the Allies' Combined Bomber Offensive was doing the job that Zeppelin and Gotha had attempted last time. If you want to demonise Dresden, you must in logic seek to outlaw aerial bombing generically. That's precisely what the League of Nations explored, 1929-33. But when one Nation was suspected of seeking monopoly advantage, we good guys had to gird. CBW was/is in that category...and in February and August,1945 when rubble had removed their fear of our retaliation, Germany/Japan could have put up a last barricade of spores, to choke the invader to stalemate. Hitler is believed to have ordered exactly that in Berlin in May,1945.