ON OCT. 14, a U.S. drone strike in southeastern Yemen took the lives of nine people, including Ibrahim al-Banna, a senior operative with al-Qaeda in the Arabian Peninsula and the intended target of the strike. Another casualty: Abdulrahman al-Awlaki, a 16-year-old American and the son of radical cleric and AQAP agent Anwar al-Awlaki. The elder Awlaki, also a U.S. citizen, was targeted and killed Sept. 30 in another attack.

An Obama administration official says the United States did not know that the teenage Awlaki was among the group traveling with Mr. Banna. But what if it had? Would the administration have changed course, had it known that a 16-year-old American was among those likely to be killed?

Administration officials, including State Department legal adviser Harold Koh, have outlined the factors that play a role in launching targeted attacks against a foreign national on foreign soil. Mr. Koh, for example, has said that such strikes would be carried out only if the targeted individual presented an imminent threat, the foreign country in question was unable or unwilling to act, and capture was not feasible. But no one in the administration has spoken publicly about what additional factors — if any — must be weighed when an American is the target. And no mention has been made about whether any special consideration must be given to an American who may become “collateral damage.” The administration also has not publicly addressed how age may factor into a decision to strike.

We believe that international and domestic laws allow targeted killings as a means of national self-defense. These attacks must be subject to rigorous checks, in part to prevent needless harm to innocent civilians, both foreign and American. U.S. citizens who take up arms with the enemy forfeit their rights to due process. The government should make every effort to alert the individual of his status as a target and to capture him, if at all possible; that obligation is all the more profound when a minor is involved. As with any operation of this type, the government has a legal and moral obligation to limit collateral damage to the greatest extent possible.

The Justice Department’s Office of Legal Counsel drafted a memorandum last year that examined the legal framework that governs targeted attacks involving an American. The administration should release the document, with appropriate redactions if necessary. The country deserves an explanation of the laws and procedures that inform the administration’s decisions.