It's because killing unarmed soldiers during war is not a war crime. Rule 3. All members of the armed forces of a party to the conflict are combatants, except

It's because killing unarmed soldiers during war is not a war crime. Rule 3. All members of the armed forces of a party to the conflict are combatants, except medical and religious personnel. https://ihl-databases.icrc.org/en/customary-ihl/v1/rule3 https://ihl-databases.icrc.org/en/customary-ihl/v1/rule3 Rule 47. Attacking persons who are recognized as hors de combat is prohibited. A person hors de combat is: (a) anyone who is in the power of an adverse party; (b) anyone who is defenceless because of unconsciousness, shipwreck, wounds or sickness; or (c) anyone who clearly expresses an intention to surrender; provided he or she abstains from any hostile act and does not attempt to escape https://ihl-databases.icrc.org/en/customary-ihl/v1/rule47 https://ihl-databases.icrc.org/en/customary-ihl/v1/rule47 A surprise drone attack on any Russian combatant that isn't a medic or chaplain is "lawful", even if they aren't holding a weapon at the time.