Yeah, there's nothing quite like genocide to win over the hearts and minds when nation building...
Who said anything about "genocide"? Did the Allies engage in "genocide" during WWII by waging a
"no more half measures, Walter" kind of war on Nazi Germany and Imperial Japan?
Yes.
The bombing of Axis cities was clearly genocidal.
The Allies didn't do it first, or worst, but they didn't resile from it, and many of those directly responsible (such as "Bomber" Harris) didn't even pretend particularly hard that that wasn't the plan. 'Worker's housing' was an explicit target, with nobody labouring under the illusion that the workers were not at home at the time.
Genocide doesn't stop being genocide when it's done by people on the right side of a war. And strategic bombing of civilians did little or nothing to help the war effort. All parties held the absurd idea that when we bomb them, it will terrify them into suing for peace; While recognising that when they bomb us, it only hardens our resolve to never surrender.
Some still cling to this insane and internally contradictory doctrine, as demonstrated by Americans responding to 9-11 with both a determination never to let the terrorists win,
and calls for retaliatory military action against the nation(s) that were imagined to have produced the terrorists.