So we should let Islamist terrorists continue launching missiles from schools?
The sad truth is that the American assassination campaign is little better than one that would be carried out using car bombs. Though had those methods been used it would be much easier to place in a more accurate moral context.
Other than that, I'd like to echo the obvious [citation needed]. Which terrorists are launching missiles from what schools at whom? And did someone actually authorize a drone strike on a school in retaliation?
I should think that it's pretty clear that if you blow up a school, you're probably evil no matter your reasoning. I'm not saying there never has been or will be a case to blow up a school, but you'd better be pretty damn sure.