The short answer is yes.
For purposes of international law, Article 51 of the United Nations Charter clearly provides states with a right of self-defense:
Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.
bin Laden claimed credit for the attack on 9/11, the largest loss of life on American soil caused by foreign attack. His killing was a legitimate response to the attack. As Lindsey Graham said this week:
“From a Navy SEAL perspective, you had to believe that this guy [Osama bin Laden] was a walking IED,” an improvised explosive device, said Graham.
“I think the SEALS had to believe that the moment they encountered [bin Laden] that they were well within their right. Shooting him as soon as possible probably protected everyone, including the SEALS, women and children,” he said. “The moment they saw bin Laden they had to consider him a threat. “
As for US law, there are several bases for the action’s legality. First, Section 2(a) of Public Law 107-40, Authorization for Use of Military Force, authorizes the President to “to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001.” bin Laden, having admitted responsibility for the 9/11 attacks, certainly qualifies as a person who planned or authorized the attack. And he repeatedly stated he would plan future attacks.
Second, bin Laden was essentially a war general. As such, he was subject to military targeting.
Ilya Somin, a professor at George Mason University’s School of Law, echoed Greenberg’s argument that “targeting individual enemy combatants in war is perfectly legal and moral”.
Somin points at US targeting of Admiral Isoroku Yamamoto, the commander of the Japanese fleet during World War II, and the British and the Czechs’ killing of German SS General Reinhard Heydrick in 1942, as precedents.
“Surely international law does not give terrorist leaders greater protection than that enjoyed by uniformed soldiers such as Admiral Yamamoto.”
“And if it is legal to individually target the commander of a uniformed military force, it is surely equally legal to target the leader of a terrorist organisation, including Osama bin Laden,” he told Al Jazeera.
Notwithstanding the foregoing, torture is never legal under either US domestic and treaty law. When an alleged combatant is captured it is not lawful to subject the prisoner to torture. There are no exceptions.
The United States has always prohibited the use of torture in our Constitution, laws executive statements and judicial decisions. We have ratified three treaties that all outlaw torture and cruel, inhuman or degrading treatment or punishment. When the United States ratifies a treaty, it becomes part of the Supreme Law of the Land under the Supremacy Clause of the Constitution.
The Convention Against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, says, “No exceptional circumstances whatsoever, whether a state of war or a threat of war, internal political instability or any other public emergency, may be invoked as a justification for torture.”
Whether someone is a POW or not, he must always be treated humanely; there are no gaps in the Geneva Conventions. He must be protected against torture, mutilation, cruel treatment, and outrages upon personal dignity, particularly humiliating and degrading treatment under, Common Article 3.
The Common Article III of Geneva Convention, of which the US is a signatory, provides, in part, as follows with respect to prisoners of war defined as individuals who have “fallen under the power of the enemy”:
Prisoners of war must at all times be humanely treated. Any unlawful act or omission by the Detaining Power causing death or seriously endangering the health of a prisoner of war in its custody is prohibited, and will be regarded as a serious breach of the present Convention. In particular, no prisoner of war may be subjected to physical mutilation or to medical or scientific experiments of any kind which are not justified by the medical, dental or hospital treatment of the prisoner concerned and carried out in his interest.
Likewise, prisoners of war must at all times be protected, particularly against acts of violence or intimidation and against insults and public curiosity.
Measures of reprisal against prisoners of war are prohibited.
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No physical or mental torture, nor any other form of coercion, may be inflicted on prisoners of war to secure from them information of any kind whatever. Prisoners of war who refuse to answer may not be threatened, insulted, or exposed to unpleasant or disadvantageous treatment of any kind.
In other words, torture of a prisoner already under a government’s total control is never a legal form of self-defense.