According to the New York Times, the unsigned and undated Justice Department white paper, published this week by NBC News, “is the most detailed analysis yet to come into public view regarding the Obama legal team’s views about the lawfulness of killing, without a trial, an American citizen whom executive branch officials decide is an operational leader of al Qaeda or one of its allies.”

The proviso is they must pose “an imminent threat of violent attack against the United States.” If “an informed, high-level official” of the government decides they are a threat, the paper says, and if capture is not feasible, they may be killed.