05/09/2011 04:47 pm ET Updated Jul 09, 2011

After Bin Laden, Time for Clear U.S. Policy on Targeted Killing

The U.S. has killed hundreds of individuals in targeted killings, many outside traditional battlefields. It conducts these killings largely in secret, without public oversight, and without any clear legal justification. The CIA operation that killed bin Laden last week is but one instance of a tactic that has now become regular practice.

This was not always the case. The U.S. officially outlawed assassination in 1976 and used to criticize targeted killings by other countries. But in the aftermath of bin Laden's terror attack, both the Bush and Obama administrations have increasingly resorted to the tactic and defended it as lawful. In fact, under the Obama administration, targeted killings have escalated substantially, mostly through drone strikes in Pakistan, which killed an estimated 900 people last year alone. Only days after the operation against bin Laden, the U.S. conducted a drone strike in Yemen, targeting an alleged member of al-Qaeda in the Arabian Peninsula, Anwar al-Awlaki.

Despite this shift and a dramatic expansion of the use of targeted killings, the U.S. has been virtually silent on the legal basis for such attacks, particularly in places most would not describe as battlefields. U.S. officials defend such killings, including the operation against bin Laden, but only in general terms, offering little more than assurances that killings are permitted under international and domestic law.

As a result, critical legal questions remain unanswered:

Where can the U.S. conduct targeted killings?
According to the Obama administration, the U.S. is not in a "global war on terror." But where exactly can the U.S. conduct armed attacks and what are the boundaries of the conflict with al-Qaeda and the Taliban? If the U.S. can carry out armed attacks in Abbottabad, can it do the same in London?

Who is the U.S. at war with and who can it target?
"Al-Qaeda, the Taliban and associated forces" says the U.S. -- but these are not top-down, clearly delineated or allied organizations. Membership in these groups and alliances between them are difficult to define and determine. The U.S. can also only attack combatants in an armed conflict. But how does it define a combatant? Where does the U.S. draw the line between civilians that might provide non-military support (relatives giving shelter, political leaders) and those that actually fight?

When can the U.S. violate the sovereignty of another country?
The U.S. contends it can do so when countries are unwilling or unable to prevent attacks from its territory. Not only do many disagree with this assertion, but what exactly is the standard and who decides when another country is 'unwilling or unable?'

Taken together, these answers demarcate the scope and limits of targeted killing. In other words, when the U.S. can use lethal military force, as it does in war, as opposed to police actions, which should almost always be the case outside of conflict zones.

Now, with the killing of Osama bin Laden, the U.S. is in a historic moment, which it should use to publicly state its policy on targeted killing.

With almost every government in the world voicing support for the U.S. operation against bin Laden, the U.S. has a unique opportunity to set a powerful precedent. Such a precedent would constrain not only the U.S., but rivals such as North Korea and Iran. Strategically, the U.S. would be wise to end the current legal vacuum that only emboldens other, often abusive regimes to expand the use of targeted killings.

Laying out its targeted killing policy would also help fill a widening gap in the law, which creates uncertainty for ordinary civilians residing in conflict zones trying to stay out of harms way, and raises concerns among military and intelligence personnel who could face legal liability for their actions.

Emerging debates over the legality of the bin Laden operation also highlight the need for clear policy. Many have expressed concern over whether bin Laden was armed when he was shot, or whether he should have been captured, if possible. Yet these debates frequently confuse different legal standards applicable in military and law enforcement operations -- and obscure fundamental disagreements over what legal framework applies to counter-terror operations and the legal limits to the use of military force. What is needed is an informed, public debate over when and where the U.S. can engage in targeted killing.

The killing of bin Laden does not mean the end to conflict with terrorists and militants or an end to the use of targeted killing operations in Pakistan, Yemen or elsewhere. But it should mark an end to years of secret targeted killings, conducted outside of public view and with no clear legal policy that sets out principles and parameters that govern its use.

Having killed the world's most notorious terrorist and criminal in a cross-border "kill operation," likely without state consent -- and with the world largely in support -- U.S.-targeted killing is at the center of public attention and international scrutiny. Now is the time to turn another page in the post-9/11 world and for the U.S. to publicly announce a clear policy on targeted killing.