The morality is in deciding when it is worth ending a human life. What tool you use is a distant second, at best. In war, once you have decided to kill a person, the moral course is to kill them as quickly and effectively as possible. Preferably with as little pain as possible.

The tools are horrible, because war is horrible. If you're opposed to their use, you need to act at the political level (to stop unnecessary war from happening) or the strategic level (to win the conflict in a way that does not require direct, physical confrontation)