Im not defending some of the bombings by the USA, but they were against a country that was in alliance to the Nazi's, and that had attacked a US base. The US went overboard in what they did to the Japanese, granted. But their actions are
less evil than what Hitler, Mengele and the other Nazi's did. Hitler was the main instigator of the whole war in the first place, causing millions upon millions of deaths across many countries, and specifically targeted multiple groups (mainly Jews) of people based on religious, ethnic or other characteristics (mentally ill, homosexuals, etc), and had them enslaved and executed. The US had camps for Japanese in America, which were also unjust, but they weren't nearly as terrible in comparison to the atrocities at concentration camps run by the Germans. Throwin' up babies and shooting them out the air like discs...burning people alive...performing ridiculous "scientific" experiments. The US targeted the Japanese on the basis of them being at war with Japan. The Germans targeted Jews (and others as aforementioned) for many reasons, such as religious hate, economic scapegoating, supposed derisiveness and deceitfulness on an individual level and on a larger, more conspiratorial level, amongst other things, most of which was spawned by psychotic cult figures as the heads of a nation primarily full of sheep and lackeys who did their billings and propagated the demonic rhetoric to astronomical proportions. There was no direct government able to defend the groups of people targeted because the countries that didn't get down with the Nazis got steamrolled quick, and/or didn't feel strongly enough about the groups targeted to defend them. Japan willfully joined this movement, supported it's major forces, and put their citizens in peril by doing so.
I think we do need to do a "which massacre is worse" thing because the thread is titled "What the United States did to the Japanese was worse (grammar) just as bad as Hitler did to Jews. That directly issues a comparison to both massacres.