Lawfulness of a Lethal Operation Directed Against a U.S. Citizen Who Is a Senior Operational Leader
I think a significant number of people are basing their opinions entirely on news reports in all its hyperbolic glory.
Perhaps a look at the actual DoJ White Paper is in order?
Lawfulness of a Lethal Operation Directed Against a U.S. Citizen Who Is a Senior Operational Leader of Al-Qa'ida or An Associated Force
Source
Excerpts
This white paper sets forth a legal framework for considering the circumstances in which the U.S. government could use lethal force in a foreign country outside the area of active hostilities against a U.S. citizen who is a senior operational leader of al-Qa'ida or an associated force[1] of al-Qa'idathat is, an al-Qa'ida leader actively engaged in planning operations to kill Americans.
Here the Department of Justice concludes only that where the following three conditions are met, a U.S. operation using lethal force in a foreign country against a U.S. citizen who is a senior operational leader of al-Qa'ida or an associated force would be lawful: (1) an informed; high level official of the U.S. government has determined that the targeted individual poses an imminent threat of violent attack against the United States; (2) capture is infeasible, and the United States continues to monitor whether capture becomes feasible; and (3) the operation would be conducted in a manner consistent with applicable law of war principles. This conclusion is reached with recognition of the extraordinary seriousness of a lethal operation by the United States against a U.S. citizen, and also of the extraordinary seriousness of the threat posed by senior operational al-Qa'ida members and the loss of life that would result were their operations successful.
The President has authority to respond to the imminent threat posed by al-Qa'ida and its associated forces, arising from his constitutional responsibility to protect the country, the inherent right of the United States to national self defense under international law, Congress's authorization of the use of all necessary and appropriate military force against this enemy, and the existence of an armed conflict with al-Qa'ida under international law. Based on these authorities, the President may use force against al-Qa'ida and its associated forces. As detailed in this white paper, in defined circumstances, a targeted killing of a U.S. citizen who has joined al-Qa'ida or its associated forces would be lawful under U.S. and international law. Targeting a member of an enemy force who poses an imminent threat of violent attack to the United States is not unlawful. It is a lawful act of national self defense. Nor would it violate otherwise applicable federal laws barring unlawful killings in Title 18 or the assassination ban in Executive Order No 12333.
Were the target of a lethal operation a U.S. citizen who may have rights under the Due Process Clause and the Fourth Amendment, that individual's citizenship would not immunize him from a lethal operation. Under the traditional due process balancing analysis of Mathews v. Eldridge, we recognize that there is no private interest more weighty than a person's interest in his life. But that interest must be balanced against the United States' interest in forestalling the threat of violence and death to other Americans that arises from an individual who is a senior operational leader of al-Q'aida or an associated force of al-Q'aida and who is,engaged in plotting against the United States.
The paper begins with a brief summary of the authority for the use of force in the situation described here, including the authority to target a U.S. citizen having the characteristics described above with lethal force outside the area of active hostilities. It continues with the constitutional questions, considering first whether a lethal operation against such a U.S. citizen would be consistent with the Fifth Amendment's Due Process Clause, U.S. Const, amend. V. As part of the due process analysis, the paper explains the concepts of "imminence," feasibility of capture, and compliance with applicable law of war principles. The paper then discusses whether such an operation would be consistent with the Fourth Amendment's prohibition on unreasonable seizures, U.S. Const, amend. IV; It concludes that where certain conditions are met, a lethal operation against a U.S. citizen who is a senior operational leader of al-Qa'ida or its associated forcesa terrorist organization engaged in constant plotting against the United States, as well as an enemy force with which the United States is in a congressionally authorized armed conflictand who himself poses an imminent threat of violent attack against the United States, would not violate the Constitution. The paper also includes an analysis concluding that such an operation would not violate certain criminal provisions prohibiting the killing of U.S. nationals outside the United States; nor would it constitute either the commission of a war crime or an assassination prohibited by Executive Order 12333.