The United States adopted targeted killing as a tactic to pursue those responsible for the terrorist attacks of September 11, 2001. The Pentagon and the Central Intelligence Agency have employed the controversial practice with more frequency in recent years, both as part of ongoing combat operations in Iraq and Afghanistan, as well as in counterterrorism efforts in Pakistan, Yemen, and Somalia. Since assuming office in 2009, Barack Obama's administration has escalated targeted killings, primarily through an increase in unmanned drone strikes on Al-Qaeda and Taliban leadership, but also through an expansion of US Special Operations kill/capture missions. The successful killing of Osama bin Laden in a US Navy SEAL raid in May 2011 and the drone strike on Al-Qaeda's number two, Atiyah Abd Rahman, in August 2011 are prime examples of this trend. The White House points to these outcomes as victories, but critics continue to condemn the lethal tactic on moral, legal, and political grounds. Despite the opposition, most experts expect the United States to boost targeted killings in the coming years as military technology improves and the public appetite for large-scale, conventional armed intervention erodes. What are targeted killings? According to a UN special report on the subject, targeted killings are premeditated acts of lethal force employed by states in times of peace or during armed conflict to eliminate specific individuals outside their custody. "Targeted killing" is not a term specifically defined under international law, but gained currency in 2000 after Israel made public a policy of targeting alleged terrorists in the Palestinian fighers. The particular act of lethal force, usually undertaken by a nation's intelligence or armed services, can vary widely-from car bombs to drone strikes to special operations raids. The primary thrust of US targeted killings, particularly through drone strikes, has been on Al-Qaeda and Taliban leadership networks in Afghanistan and the remote tribal regions of Pakistan. What are the legal considerations surrounding US targeted killings? The Bush and Obama administrations have sought to justify targeted killings under both domestic and international law. The Obama administration expounded its stance most notably in March 2010, stating that the United States remains in "armed conflict with Al-Qaeda, as well as the Taliban and associated forces, in response to the 9/11 attacks, and may use force consistent with its inherent right of self-defence under international law." The White House asserts that the US right of self-defence, as enumerated in Article 51 of the UN charter, may include the targeted killing of persons such as high-level Al-Qaeda leaders who are planning attacks, both in and out of declared theatres of war. The administration's posture includes the prerogative to unilaterally pursue targets in states without their prior consent if that country is unwilling or unable to deal effectively with the threat. The US raid that killed Osama bin Laden in Abbottabad, Pakistan, is demonstrative of the Obama administration's policy, which some have condemned as a violation of national sovereignty, given that Washington chose not to notify Islamabad of the incursion. Philip Alston, the former UN special rapporteur on extrajudicial, summary, or arbitrary executions, condemns the US claims of self-defence as overly expansive, stating that "if other states were to claim the broad-based authority that the United States does, to kill people anywhere, anytime, the result would be chaos." Matthew Waxman, a CFR expert on international law, says that while the strike on bin Laden would normally be a violation of state sovereignty, the US government "is well within its rights" to use force on foreign soil without consent if there is an overriding necessity of self-defence. As a matter of domestic law, the legal underpinning for US counterterrorism operations and the targeted killing of members of the Taliban, Al-Qaeda, and its affiliates across the globe is the 2001 Authorisation for the Use of Military Force (AUMF), which the US Congress passed just days after 9/11. The statute empowers the president "to use all necessary and appropriate force" in pursuit of those responsible for the terrorist attacks. The United States has had an official ban on peacetime assassinations since 1976; however, targeted killings are not subject to the prohibition because of the AUMF, insofar as US responses to the events of September 11, 2001, are concerned. In addition, by classifying terrorism as an act of war, rather than as a crime, the government is not bound by the legal constraints of due process. CFR national security expert John B. Bellinger says the law is in need of a significant update. "The 2001 AUMF is ten years old now and getting a little long in the tooth-still tied to the use of force against the people who planned, committed, and or aided those involved in 9/11," he says. "The farther we get from [targeting] Al-Qaeda [e.g., al-Shabaab in Somalia], the harder it is to squeeze [those operations] into the AUMF." As of August 2011, Congress is debating a 2012 National Defence Authorisation Act that seeks to drop any reference to 9/11 in the AUMF and reaffirm a state of armed conflict (Politico) with Al-Qaeda and associated forces. The United States maintains that targeted killings are consistent with "law of war" principles, chiefly those of distinction and proportionality. In a 2010 speech, Harold Koh, legal adviser of the US Department of State, said distinction requires attacks be limited to military objectives, and that civilians and civilian buildings not be targeted. Proportionality, he added, prohibits attacks expected to cause undue collateral damage relative to the military advantage gained. What methods of targeted killing does the United States employ? * Drone Strikes Targeted attacks launched from unmanned aerial vehicles, or drones, have ballooned under the Obama administration. A study undertaken by the New American Foundation reports that in his first two years of office, President Obama authorised nearly four times the number of strikes in Pakistan as President Bush did in his eight years. The report, which relies solely on media accounts of attacks, claims that some 225 strikes have been launched since 2009, killing somewhere between 1,100 and 1,800 militants (as of August 2011). While alternate reports (BIJ) also document the escalation in drone strikes in recent years, the accounting of militant and civilian deaths can vary widely depending on the source. Traditionally the CIA has managed the bulk of US drone operations outside recognised war zones, such as in Pakistan, while the Defence Department (DOD) has commanded operations in established theatres of conflict, such as in Iraq, Afghanistan, and Libya. But in some instances, the drone operations of both the CIA and DOD are integrated, as in the covert drone campaign in Yemen (WSJ), where the United States is marshalling counterterrorism forces in the wake of recent political unrest. * Kill/Capture Missions Since President Obama assumed office, the Pentagon has also increased the use of special operations raids (aka kill/capture missions) from 675 covert raids (ArmyTimes) in 2009 to 1,879 so far in 2011. According to the Pentagon, approximately 84 to 86 percent of these night raids end without violence (NationalJournal). NATO officials report that the target is successfully killed or captured (WashPost) 50 to 60 percent of the time. As conventional US forces begin to drawdown, "the role of counterterrorism operations, and in particular these kinds of special missions, will become prominent," says ISAF commander General John Allen. The covert raids are directed by an elite element within the US military known as Joint Special Operations Command (JSOC). The clandestine command draws top personnel from groups like the Navy SEALs and Army Delta Force and maintains a direct relationship with the executive branch. JSOC has tripled in size since 9/11 and currently operates in a dozen countries. Jeremy Scahill of The Nation writes, "The primacy of JSOC within the Obama administration's foreign policy-from Yemen and Somalia to Afghanistan and Pakistan-indicates that he has doubled down on the Bush-era policy of targeted assassination as a staple of US foreign policy." What are the political implications of US targeted killing? A prominent criticism of US targeted killings, and of drone strikes in particular, is over the issue of collateral civilian deaths. Some official Pakistani sources claim that seven hundred innocents were killed in 2009 alone, while US government sources claim that fewer than thirty civilians were killed from May 2008 to May 2010. Writing in Foreign Affairs, Peter Bergen says the more salient question is, "What impact has the drone program in Pakistan and, by extension, that in Afghanistan?" Violence in Pakistan has risen sharply since the drone campaign began, according to the US National Counterterrorism Centre, however Bergen adds that "a number of factors could have contributed to these increases." Other critics suggest targeted killings are counterproductive and a bane to US - Pakistan relations. Imran Khan, a member of the Pakistani opposition, says that drones strikes and similar US tactics breed more terrorism. Civilians and local governments also condemn night raids as culturally offensive, given that US soldiers enter homes in the dead of night, with women present, and utilise dogs (which are viewed as impure) in their search. Afghan President Hamid Karzai (WashPost) has called for a reduction in these covert missions and demanded that local soldiers take over the role. Proponents of targeted killings say the civilian death toll is exaggerated for political purposes and claim drone strikes and night raids remain the most effective and discreet tactics in pursuing militant leaders and their networks, especially as the United States begins to seek a smaller military footprint in the region. Daniel L. Byman of the Brookings Institution says that targeting top terrorists like bin Laden removes charismatic and pragmatic leaders who are difficult to replace. In addition, by targeting an Organisation's lieutenants, "it is possible to exhaust the terrorist group's bench." CFR's Micah Zenko says that while drone strikes are an effective military tactic, "military victory is not tantamount to political success." He says that while a policy of leadership decapitation can reduce "a group's capacity, it neither ruptures group cohesion nor ideological commitment." What is the future of targeted killings? Blowback from civil liberties and human rights groups is likely to grow in direct proportion to any increase in targeted killings. Organisations such as the ACLU and Human Rights Watch have raised pointed questions regarding the perceived lack of accountability and transparency. Others question if the United States is setting a negative precedent that will be invoked by other nations (WashPost) acquiring similar technology, such as China and Russia. CFR's Bellinger expects targeted killings to become much more politically provocative given the Obama administration's current posture, and asks if drones will "become Obama's Guantanamo?" Nevertheless, analysts point to several factors indicating that an expansion of US targeted killings in the near term is likely. Drone strikes and special operations raids put fewer Americans in harm's way and provide a low-cost alternative to expensive and cumbersome conventional forces. This alternative is further enhanced given the probability of future cuts in the defence budget and a waning public appetite for long, expensive wars. The rise of the so-called "non-state actor," operating in loose transnational networks, as the principal threat to US national security also lends itself to an expansion of US targeted killings. Other experts say technological advances, including precision-guided munitions and enhanced surveillance, have given the United States a greater ability to target these particular individuals while reducing collateral damage. In July 2011, Obama's chief counterterrorism advisor, John Brennan, provided a portent of things to come: "Going forward, we will be mindful that if our nation is threatened, our best offence won't always be deploying large armies abroad but delivering targeted, surgical pressure to the groups that threaten us." Council on Foreign Relations