Back at CIA headquarters in Langley only the "reachback operators" – the men with joysticks sitting at monitors controlling the pilotless drone – and the intelligence officers standing alongside, would have witnessed the last moments in the life of Abu Yahya al-Libi.
Perhaps they saw some al-Qaeda men on the ground looking skywards having heard the buzzing sound of the "machay" – meaning "wasps" – as locals in the Pashtun language of Pakistan's North Waziristan Province have nicknamed the drones.
Had the terrorists realised they, too, were under imminent attack, the CIA officers might also have seen them run for cover. Drone operators refer to those fleeing the kill zone as "squirters".
Whatever happened in those final moments last Tuesday the outcome we know for certain. The compound and vehicle targeted by the drone's missiles in the village of Hesokhel, near Miranshah, were eviscerated along with Abu Yahya al-Libi.
Known as the "gatekeeper" because of his role as the conduit between the terrorist group's leadership and its footsoldiers, Libi was al-Qaeda's second in command and a "high value" CIA target.
As with every drone strike operation, the go-ahead for Libi's assassination would have been made at the very highest level, by President Barack Obama.
At least once a week – "Terror Tuesday" – at the White House Situation Room, Obama is said to meet with US intelligence heads during which he pores over lists and portrait pictures nicknamed "baseball cards" of possible terrorist targets.
Ultimately, it is Obama himself that will make the grim call on who will be targeted from the "kill list", but not before an often lengthy and rigorous inter-agency process that could involve the Pentagon, the state department, CIA and the National Security Council.
While individual cases can be debated for weeks, the exchange of intelligence and views leads to "nominations" for death-marked finalists leading to the "personality strikes" that kill them.
Then there are those known as "signature strikes" or "crowd kills" that target a group of people whose names may not be known but whose behaviour and activities monitored from drone aerial surveillance pictures show them to be a danger.
The US government runs two drone programmes. There is the military version, operating in recognised war zones and publicly acknowledged as an extension of conventional warfare, in that it targets enemies of US troops in the battlefield.
Then there is the much more controversial, covert CIA programme cloaked in secrecy and aimed at terrorist suspects even in countries where no US troops are deployed.
In his book Kill Or Capture: The War On Terror And The Soul Of The Obama Presidency, author Daniel Klaidman describes how Obama along with James "Hoss" Cartwright, the four-star Marine general and vice-chairman of the Joint Chiefs and top counter-terrorism aide, John Brennan, form a kind of special troika on targeted killings. For this decision-making trio, security and operational considerations often mean there is little time for lengthy debate and a call has to be made quickly.
It is said Obama has been known to respond with a little gallows humour when Cartwright or Brennan show up at the Oval Office unannounced or pull the president out of black-tie dinners or track him down on a secure phone to discuss a proposed strike.
"'Uh-oh, this can't be good,' Obama would say, arching an eyebrow," according to Klaidman's book.
Back in the hills of Afghanistan and Pakistan or the deserts of Somalia and Yemen it is often aerial surveillance drones that are the first contact with the target, relaying the co-ordinates to an operations centre, where personnel would consult maps and speak to senior intelligence officers in an attempt to identify civilian structures and any other considerations for a possible strike.
With such a consultation complete and the green light given for a mission, the operations centre would relay instructions to an airborne drone.
This process, also known as the "kill chain" or "sensor-to-shooter cycle", can take days – but where armed drones are used and the target needs to be hit imminently the kill chain is only one link long and the process takes less than five minutes.
Within the CIA, control of the drones and operations are shared by several teams. One set of operators works within the battlezone, often at airfields in places like Afghanistan handling take offs and landings. During one of my own stays at Jalalabad airfield in Eastern Afghanistan near the Pakistan border, I well remember watching from my accommodation hut that sat adjacent to the runway the Predator drones coming and going.
On one occasion a returning drone with a damaged undercarriage had to be flown out beyond the airfield to drop its payload of weapons, which were then recovered by special forces troops, before it could be landed safely.
Others I watched taking off fully armed returned only a little while later having covered the short flying distance to their targets most likely inside Pakistan's tribal areas that run along the frontier with Afghanistan.
Once in the air the controls of the drones are electronically "slewed over" to a set of "reachback operators" at CIA headquarters in Langley. Much has been made of the "push-button" anonymity of such killing done by drone operators from the comfort of an American base.
"I hear you guys have a PlayStation mentality," State Department legal adviser, Harold Koh, is said to have told a group of drone pilots during a meeting, according to author Daniel Klaidman. The answer he received from one "pilot" was a rare insight into the role of the drone operator and what it takes to do such a job.
"I used to fly my own air missions," he said. "I dropped bombs, hit my target load, but had no idea who I hit. Here I can look at their faces. I watch them for hours, see these guys playing with their kids and wives."
In an account not unlike that you might hear from a infantry sniper who sees his targets through a scope, the drone operator told how after the strike he often watched on the monitor as the bodies are carried from the rubble or womenfolk wept and mourned over the dead.
"That's not PlayStation – that's real," insisted the operator.
In the kill zone itself the effects of the drone's lethal Hellfire missiles is all too painfully real. According to some latest reports, Barack Obama has ordered a "sharp increase" in drone strikes in Pakistan's tribal areas. This coming Tuesday, as they do at the same time every week, the US president and his men will once again pore over the files of the "kill list".
In the days that follow it's pretty much a given that terrorists of al-Qaeda's global franchise from Pakistan to Yemen will suffer a similar fate to Abu Yahya al-Libi.
By Diplomatic Editor Trevor Royle
Killing is rarely an impersonal business. In modern warfare with its array of high-powered weapons the act can be distorted by the distance between killer and victim, but even that cannot guarantee clinical detachment.
That's why there is growing concern about the use of unpiloted drones which kill silently and without warning, the only people responsible being anonymous operators thousands of miles away whose only view of the target is the screen in front of them. These missile-armed drones are the ultimate fire-and-forget weapons system.
They are also battlefield multipliers in that they give commanders on the ground a better chance of taking out the opposition. In Afghanistan they have killed several high-value al-Qaeda commanders and more recently they have also been deployed in Yemen where the regime is receiving US military assistance in its long-running war against al-Qaeda in the Arabian Peninsula (AQAP).
In both cases an added attraction is that they do not put US lives at risk and do not require the presence of boots in the ground, both important factors in managing low-intensity wars which are usually unpopular back home. From a military point of view drones are an important part of the arsenal in any modern army and have been welcomed by battlefield commanders on the ground. But looking at them as objectively as possible, there are growing doubts about the ethics and the legality of using weapons of this kind.
First, the morality. There have always been bogey weapons which seem too unfair or too disgusting to be used against human beings. Flame-throwers firing napalm come into this category and so did tanks and machine guns when they were first brought into use. Drones now have to be included because they kill in a clinical and detached way, and also because they kill indiscriminately. In one of the most recent attacks in the Afghan theatre of operations, the intended target Abu Yahya al-Libi, described as al-Qaeda's second in command, was killed but so were 17 civilians. It's a common occurrence.
Secondly, there are growing concerns about the legality of these weapons, not just in Afghanistan but also in neighbouring Pakistan, a known haven for al-Qaeda and Taliban warlords. Last week, during a visit to Pakistan, Navi Pillay, the UN high commissioner for human rights, suggested the government should invite a UN special rapporteur on extrajudicial, summary or arbitrary executions to visit the country to examine the legality of missile attacks by drones in the troubled tribal areas near the Afghan border.
She has a point. There is growing concern about the legitimacy of attacking targets in a friendly country especially when innocent bystanders are also killed. Pakistan is a key US ally even if it is not always trusted in Washington. Pillay's intervention has also been spurred by the fact that drone attacks have not been made under military supervision but have been directed by the CIA, which until recently did not even admit drone operations existed.
In her view this has muddied the waters because under international law it is extremely difficult to ensure accountability when operations are conducted outside the normal military chain of command, and in this case involve an intelligence agency. Pillay's case rests on the point that this kind of operation infringes international law and abuses the human rights of the victims. In theory at least, the British equivalent MI6 is banned from mounting operations which involve targeted killing.
Any UN intervention will probably not halt drone operations in the short term but in the longer term a rapporteur could cause problems simply because scrutiny of any alleged abuse of human rights is always an embarrassment to the country under investigation. What will probably let the US off the hook is the need to maintain secrecy in operations against al-Qaeda and Pakistan's own flaky record in dealing with militants and alleged enemies of the state who all too often simply "disappear".
Pillay insisted the rapporteur should investigate a "spate of killings" in Pakistan not just by militias and criminals but also by "state military intelligence agencies", the inference being that these cases – like the drones – breach international law and abuse human rights.
By Andrew Purcell in New York
IN the first summer of Barack Obama's presidency, as Democrats struggled to pass a bill for universal health care, Sarah Palin expressed Republican fears by coining the phrase "death panels" in claiming bureaucrats would be given the power of life or death over patients. Her warning had no basis in fact, but it proved effective in defining "socialised medicine" as a government assault on the individual rights of Americans.
Republicans were relentless in their use of the term, so it is striking that there has been nothing but praise for the President, from both sides of the aisle, following revelations of a real death panel. It meets every Tuesday in the White House to decide who to add and who to rub off a "kill list" of suspected terrorists. National security is a rare area of bipartisan consensus in Congress: the more belligerent, the better.
In the year since Osama bin Laden was killed, Congress has renewed the Patriot Act, extending the surveillance state into every corner of American life, with barely a murmur of dissent. It has passed the National Defence Authorisation Act, which allows indefinite detention without trial. When the CIA assassinated Anwar al-Awlaki, a US citizen, on direct orders from the President, every Republican contender to challenge Obama, bar Ron Paul, said they would have done the same.
Writing in The New Republic, lawyer Jack Goldsmith, who served in the George W Bush administration, identified 11 areas in which Obama's national security policy has mirrored that of his predecessor, including rendition, targeted killings and a definition of the war on terror that strips "enemy combatants" of legal rights. "The new administration has copied most of the Bush programme, has expanded some of it, and has narrowed only a bit," Goldsmith concluded. "Almost all of the Obama changes have been at the level of packaging, argumentation, symbol, and rhetoric."
On Thursday, former Florida Governor Jeb Bush said Obama should offer "a little tip of the hat" to his brother for setting the course. General Michael Hayden, who served as CIA director under Bush, said Obama's aggressive counter-terrorism strategy had a "Nixon to China quality" – commending it as a courageous approach that defies the expectations of his supporters.
John Bellinger, a senior national security lawyer in the Bush administration, noted: "After the global outrage over Guantanamo, it's remarkable that the rest of the world has looked the other way while the Obama administration has conducted hundreds of drone strikes in several different countries, including killing at least some civilians."
Hayden and Bellinger's comments were reported in a New York Times article that revealed the existence of the "kill list" and the "nominations process" behind it. This was clearly approved by the White House, which set up an interview with Obama's national security adviser, Thomas Donilon, in which he lauded his boss as a decisive, hands-on leader. "He's a president who is quite comfortable with the use of force on behalf of the United States," Donilon said.
In this election year, national security is one of Obama's few trump cards. A recent CNN poll gave him a 52% to 36% edge over Mitt Romney on the question of who would make the best Commander-In-Chief. A Washington Post survey found that 83% of voters, including 77% of self-described liberal Democrats, support the use of drones to combat terrorism.
The Obama campaign has played to this strength. Vice-President Joe Biden has offered a "bumper-sticker" summation of the administration's achievements: "Osama bin Laden is dead and General Motors is alive." Romney's team briefly complained that Obama's trip to Afghanistan on the anniversary of bin Laden's death was a stunt, with some justification, but soon dropped the subject. For once, the ads portraying a rival as weak on national security are being run by the Democratic Party.
Democrats can barely contain their glee. Peter Bergen of the New America Foundation wrote a New York Times editorial extolling Obama as a "warrior president- one of the most militarily aggressive American leaders in decades". Michael O'Hanlon of the Brookings Institution argued that Obama has had "a better first term in the White House on foreign policy than any Democrat going back to Truman, and frankly better than most Republicans' first terms as well".
There has been criticism from the left, but their voices are easily dismissed as marginal. "Obama has normalised assassination for a lot of liberals who would have been outraged if it was President McCain- they are deafeningly silent on this issue," observed reporter Jeremy Scahill of The Nation.
Civil rights lawyer Glenn Greenwald, writing in Salon, argued that Democrats must shoulder their share of the blame for the deaths of civilians in drone attacks. "Obama has converted what were just recently highly divisive and controversial right-wing Assaults on Our Values into fully entrenched bipartisan consensus. But worse than that, he has put a prettier and more palatable face on extremely ugly policies."
Dennis C Blair, former director of national intelligence, said drone attacks will continue as long as support lasts. "It is the politically advantageous thing to do – low cost, no US casualties, gives the appearance of toughness," he told the New York Times. "It plays well domestically, and it is unpopular only in other countries. Any damage it does to the national interest only shows up over the long term."