"Just what does distinguish lawful targeted killing from unlawful political assassination? The answer turns upon which legal framework applies. During war, the law of armed conflict applies, and targeted killing of individuals is lawful, although killing by treacherous means – through the use of deceit or trickery – is not. In peacetime, any extra-judicial killing by a government agent is lawful only if taken in self-defense or in defense of others."
January 1, 1970
https://en.wikiquote.org/wiki/Targeted_killing