I don't believe you can minimize civilian damage more than that, if a target is always among civilians. You can only push so much, like the pager attack was probably the most minimizing one, but obviously and unfortunately civilians still got caught.

For the international law part, interesting debate i think, where the state acts in self-defense if it has sustained an “armed attack” by its adversary;. Obviously this is very broad, but i think you can easily argue the last 40 year of fire exchanges as a continued armed attack.

US already has the technology to target a single seat in a car with a missile that has no explosives, solely kinetics (swords really).