Sanctions as Collective Punishment

At present, we treat nations as though they were persons: We punish entire nations by sanctions, even when only the leaders are guilty, even though the burdens of the sanctions fall most heavily on the poorest and least guilty of the citizens, and even though sanctions often have the effect of uniting the citizens of a country behind the guilty leaders. Should we not regard sanctions as collective punishment? If we do so, then sanctions are a war crime, under the Fourth Geneva Convention.