It’s claimed that drone strikes in Pakistan make America safer, by surgically eliminating terrorists.
But a study published on Tuesday claims that not only are very few key targets killed, but that the attacks have resulted in high civilian casualties – including children - and have greatly increased resentment towards the US.
The report, by Stanford University and New York University, warns that the CIA's drone campaign, which has escalated under Obama, "terrorises men, women and children" in north-west Pakistan "twenty-four hours a day".
Drones constantly patrol the skies above north-west Pakistan
The detailed report - which was compiled over nine months using interviews with the local population, including victims of strikes, humanitarian workers and medical professionals – explains that hundreds of civilians have been killed through drone strikes.
It quotes figures from the London-based Bureau of Investigative Journalism (TBIJ), which says that from June 2004 to mid-September 2012, drone strikes killed between 2,562 and 3,325 people in Pakistan, of whom 474 to 881 were civilians, including 176 children.
Some of these children have been killed during Obama's incumbency, according to the TBIJ.
The number of "high-level" targets killed as a percentage of total casualties is extremely low - estimated at just 2%, the study found.
The strikes come from Predator and Reaper drones that fire powerful hellfire missiles and the deaths and injuries they’ve caused have devastated village life in Pakistan, the study says.
For example, children in the affected areas are being taken out of school for a number of reasons, including "the physical, emotional and financial impacts of the [drone] strike," "to compensate for the income lost after the death or injury of a relative," or "due to fear that they would be killed in a drone strike."
Sadaullah Khan, a 15-year-old who lost both legs in a drone strike, told researchers: "I used to go to school… I thought I would become a doctor. After the drone strikes, I stopped going to school."
A local taxi driver described how “whether we are driving a car, or we are working on a farm, or we are sitting at home playing cards – no matter what we are doing we are always thinking the drone will strike us. So we are scared to do anything, no matter what."
What’s more, rescue efforts are hampered by so called "double tap" strikes, the study says, whereby drones are directed to hit target areas twice over.
Interviewees "explained that the secondary strikes have discouraged average civilians from coming to one another’s rescue, and even inhibited the provision of emergency medical assistance from humanitarian workers".
One aid agency reported that it allows a delay of six hours before visiting a reported drone-strike scene.
The psychological impact of drone strikes is also highlighted, with some villagers explaining that they live in constant fear of being caught up in an explosion.
Some are too afraid to meet in groups of more than two, as drones tend to be directed at large gatherings and others reported that they're too scared to attend funerals.
Post-traumatic stress symptoms such as emotional breakdowns, fainting and nightmares were reported among some interviewees.
The strikes are also having a negative effect on villagers' perception of America, too, and may even be bolstering terrorist ranks.
Roughly three in four now consider the US an enemy, an increase from both 2010 and 2011, according to the study.
The authors write: "It is clear from polling and our research team’s interviews that drone strikes breed resentment and discontent toward the US, and there is evidence to suggest that the strikes have aided militant recruitment and motivated terrorist activity."
The study also calls into question how certain drone operators can be that they’re targeting a real threat.
Daniel Klaidman, in Kill Or Capture: The War on Terror and the Soul of the Obama Presidency, writes that according to US authorities, these strikes target "groups of men who bear certain signatures, or defining characteristics associated with terrorist activity, but whose identities aren’t known".
Just what those "defining characteristics" are has never been made public, the study authors say.
The US regards any male of fighting age as a legitimate target, something that may be masking the number of civilian deaths, they add.
Clive Stafford Smith, from UK-based human rights agency Reprieve, said: "This shows that drone strikes go much further than simply killing innocent civilians.
"An entire region is being terrorised by the constant threat of death from the skies. Their way of life is collapsing: kids are too terrified to go to school, adults are afraid to attend weddings, funerals, business meetings, or anything that involves gathering in groups.
"Yet there is no end in sight, and nowhere the ordinary men, women and children of North West Pakistan can go to feel safe. George Bush wanted to create a global ‘War on Terror’ without borders, but it has taken Obama’s drone war to achieve his dream."
The report does not include any references to UK involvement in drone strikes, but the former director of public prosecutions, Lord Macdonald, said recently that there was "compelling evidence" that the secret service listening post GCHQ was providing the US with intelligence about potential drone-strike targets.