One would think that the military are a bit more coolheaded about it, but there seem to be similar cases with excessive rules of engagement.
Soldiers are willing to take risks to avoid casualties but their superiors tell them to do otherwise.
The reason is obvious. The ability for the US to project power is restrained by intolerance at home for soldiers returning in coffins.
So the rules of engagement are adapted accordingly, preference for killing by remote, and in case of direct contact, when in doubt, kill.
This in the first place leads to a lot of foreign casualties, and secondly to a lot of antagonism and well, more enemies.
Actually it's more complex, because there is also only moderate tolerance for directly killing the other guys. Then again there is little objection to less direct forms of killing because it easily gets muddled and confused. We're used to the lowest estimates of casualties in Iraq before 2007, just like we're used to the highest estimates in Syria now.
There is a high tolerance for drone killings, but mostly because they're viewed as highly successful tools that make few mistakes. Which they're not.
You can't do carpet bombing anymore though. It's not tolerated.