On the Fact that (According to A.C. Grayling's Classic Volume, "Among the Dead Cities") it Wasn't Until 1977 that the Geneva Convention Summarily Condemned the Carpet-Bombing of Civilian Areas

Yeah, this was because the two countries that suffered the greatest from these atrocities, Japan and Germany, were on the losing end of the conflict and hence had precious little impact on the crafting of the document. To the victors go not just the spoils seemingly.