Not doing it properly. Unlike Assad.
Dropping barrel bombs on school children, really doing it properly eh?
Assad, blowing limbs off his own fellow countrymen's children, really doing it properly.
There is no right or wrong in war, the only properly is what you need to do to win. You do what you have to effect that means, no more, no less.
We Nuked, firebombed etc how many again in WW2.? What you need to do, is warranted by your circumstances and what is available to you.
Its all very well to be morally superior when you have every weapon under the sun available to you.
As for airpower, as much as I like to see a severe smiting Of ISIS by a few hundred thousand western ground troops, that doesn't seem like that will happen anytime soon. As such it will be targeted air power and local forces doing it. Which means a long drawn out campaign.
The big question is by local, is there enough Sunni's who may stand up when the need arises?