You're right about everything. But consider ISIS, what kind of communication should we perform that will make future groups like that stop beheading people and raping children? There are situations where violence unfortunately is the only option left, and in that case you will want it to be as targeted and clean as possible to avoid collateral damage. Currently drone strikes is the best tech for that purpose, and we have an incentive to make it better for the reasons previously mentioned.

If the US only were using drones against ISIS then that would be a different story. The fact of the matter is that the US uses drones on much less morally cut-and-dry groups than ISIS, and will likely continue to do so in the future. It's like if a farmer wanted you to make them a shotgun so they could kill the wolves terrorizing their flock but you knew they were also going to use that shotgun to rob their neighbor for oil

I see your analogy. But it's not totally perfect, because in a (hopefully functioning) democracy, the farmer can be told what to do by his constituents. Obviously this doesn't always happen, but do we trust the entity we voted for (USA.gov), or the one that makes money off our existence (google.com).

I don't always know.

War has never existed due to a lack of tools or technology. If anything, those things made war more deadly than ever (see WW1).

Wars exist because people are willing to kill and die for what they believe in. As Carl von Clausewitz wrote, “War is simply the continuation of political intercourse with the addition of other means”