Who has the "moral high ground", if such a thing exists, in such cases?
Um, nations have been using military force of whatever kind they have available -- and doing so in whatever ways minimize what they have at risk for what they stand to achieve -- for a very long time, longer than the US has been around.
Its not like Russia or China would refrain from using drones, where available, just because the US hadn't done it first.
> Who has the "moral high ground", if such a thing exists, in such cases?
The moral high ground is highly subjective, and generally perceived as being strongly linked to the validity of the justification.
Not that the moral high ground matters all that much in practice if the outrage level isn't tied to groups with both the capacity and the will to do something about it which influences the national interest calculation.
I think it is pretty clear who has the moral high ground on this one. For me this aspect of US foreign policy is by far the most disgusting, even more than the assassinations.
You can see for yourself how the US demands from Russia to stop their military campaign in Syria now that the Jihadi groups are losing ground.
The worst part, is that with all three big players lobbying warheads around in Syria, we might be closer to a third world war than we've ever been before.