For hours on end, the U.S. military watches what it calls terror targets overseas through the lenses of drones - remotely piloted aircraft flying miles above places like Pakistan and Yemen.
“We see anything from them going to the grocery store to washing their laundry outside,” one drone operator recently told VOA during a visit to a pilot training facility at Holloman Air Force Base in the U.S. state of New Mexico. “We'll watch them wake up in the morning.
After two long wars in Iraq and Afghanistan, the U.S. touts the drone program as one that allows America to eliminate terrorists without putting American soldiers in harm's way.
On the ground in Pakistan, however, where drones have struck often in recent years, the view is starkly different.
Those living in Pakistan’s north say the drone attacks too often are indiscriminate and, they say, kill civilians far more than terrorists.
“I have a message from all the tribesmen that their targets were wrong," said Habib Noor Orakazi, a tribesman from northern Pakistan. "Whatever their research was, that is absolutely mistaken.”
VOA Pentagon’s correspondent and VOA reporters in Pakistan took a comprehensive look at the impact of the U.S drone program on U.S. service personnel who operate the drones, and also on Pakistanis who suffer the consequences of the U.S. actions.
On both sides, they found stress and conviction of beliefs in the legitimacy - or not - of the strikes.
The U.S. Air Force rarely grants reporters access to drone bases, but it hosts an open house at least once a year to showcase its training efforts at the Holloman Base.
In portable buildings the size of large shipping containers, hundreds of young men and women train to become the next generation of U.S. pilots of what the Air Force calls Remotely Piloted Vehicles [RPVs]. The base is on the fringes of New Mexico's White Sands Missile Range, not far from where the United States Army tested its first atomic bomb in 1945.
This vast expanse of desert once again is the scene of experimentation of a form of warfare whose effects on pilots are only now beginning to be known, and include rates of post-traumatic stress disorder, anxiety, substance abuse, and suicide that do not differ significantly from pilots of manned aircraft.
The jagged mountains visible in the distance of the base bear a resemblance to some of those in distant regions, creating an even more realistic effect for the pilots who spend long hours each day at the controls, sitting in large chairs at consoles with video screens and joysticks.
The aircraft they are flying are Predators and Reapers, the type that are at work around the globe carrying out reconnaissance and bombing missions.
They are flown by teams of two: a pilot and a sensor operator. The latter controls all the cameras and spots targets on the ground, monitoring them often for hours and even weeks before the pilot initiates the strike.
The RPA pilot executes kill orders, but the final decision on who to strike comes from a higher command - a panel of a number of people, who can include anyone from the U.S. President to generals and intelligence officials. Their decision is based in part on the data relayed to them by the RPA crew.
“After watching a compound for so many weeks, days, months, we'll actually be able to set our watch to when they're going to wake up in the morning,” said Jeremiah, a staff sergeant identified only by his first name for security reasons.
“It is the most difficult part of the job,” he said about firing on individuals whose daily habits and routines he comes to know somewhat intimately.
In some respects, it is harder for the drone pilot crews to engage in targeted killing than it is for someone who's in an aircraft thousands of feet above the ground, said one expert in pilots’ stress.
“It's an up close personal kind of killing that takes a huge psychological toll on our soldiers and airmen,” said Audrey Kurth-Cronin, a professor at George Mason University's School of Public Policy.
Jean Otto, a Department of Defense epidemiologist who co-authored a recent report comparing mental health outcomes among U.S. Air Force RPA operators and conventional manned warplane pilots, said her findings counter a perception that because pilots are not deployed to combat, they may carry less of a mental health risk.
“We found that there was no statistically significant difference in the rate of mental health outcomes between the two groups,” Otto said.
Bradley Hoagland, a U.S. Air Force Colonel, conducted research on how the Air Force identifies and develops drone pilot candidates, as part of a fellowship at the Brookings Institution. He found they were washing out of initial flight screening at rates about three times higher.
Hoagland said there is much room for improvement when it comes to prescreening methods for a job where the challenges have yet to be fully understood.
“It's not pulling the G's in an aircraft, but what we're asking these young airmen to do to execute the mission for the RPA is intense,” he said. “You put a lot of responsibility on these young airmen's shoulders to make the right decisions.”
The drone program has been highly unpopular in countries like Pakistan, which frequently has denounced U.S. drone strikes on militants operating in the country's semi-autonomous Federally Administered Tribal Regions.
Pakistani officials allege the strikes have often killed innocent civilians and fueled the unsubstantiated perception that the strikes kill more innocent victims than militants.
The attacks have triggered large anti-American demonstrations in Pakistani cities in an effort to get Pakistan's government to ban U.S. drones from operating in Pakistani airspace.
Pakistan's Prime Minister, Nawaz Sharif, called for an end to U.S. drone strikes in a meeting with President Obama at the White House last October.
Pakistani officials say the drone attacks are counterproductive and point to their human rights and humanitarian implications.
“These drone strikes have a negative impact on the government's efforts to bring peace and stability in Pakistan and the region,” said Tasneem Aslam, a spokeswoman for Pakistan's foreign office.
Following pressure from foreign governments, as well as human rights activists in the United States, the Obama administration has scaled back drone strikes.
While U.S. government does not provide casualty figures, the New America Foundation, a Washington-based public policy group, estimates the strikes have killed up to 3,400 people in Pakistan since operations began in 2004.
The group says up to 300 of those killed were civilians, not combatants.
But among the list of prominent militants killed by U.S. drones is Hakimullah Mehsud, the leader of the Pakistani Taliban, in a hit last November.
Others include Anwar al-Awlaki, a U.S. citizen and senior official of al-Qaida in the Arabian Peninsula, killed in 2011. The second in command of that organization, Said al-Shehri, was killed in a drone stroke in Yemen last July, as were two other senior AQAP leaders the following month, also in Yemen.
A recent U.N. Report said the attacks dropped significantly last year, down to 27 strikes from a peak of 128 in 2010.
“For the first time in nine years, there were no reports of civilian casualties in Pakistan in 2013," said Ben Emmerson, the United Nations' special investigator on counterterrorism.
Emmerson, however, said a different scenario exists in Afghanistan, where the U.N. reports civilian casualties from drone strikes rose to 45 dead and 14 injured - three times as many as in 2012.
Yemen has had an estimated 500 civilian casualties from drone strikes since 2009, according to the U.N. official.
With the U.S. Air Force training RPA operators at an unprecedented rate, it appears drones will remain a weapon of choice for the U.S. military.
Matt, an Air Force pilot at Holloman, who flies both manned aircraft and RPA's, has no doubt that drones are here to stay. He said he finds his work fulfilling because it saves American troops on the ground from Improvised Explosive Devices [IEDs] and other dangers.
“It prevents folks from being hit by IEDs and we go and find the big bad guys and that is good business to be in,” he said. “It's very rewarding. I believe that RPAs are the future.”
A tribesman in northern Pakistan, Orakazi, has a different take. “God has given them so much, he said. “They have sophisticated technology, it would be great if it is used properly.”
Luis Ramirez reported for VOA News from Holloman Air Force Base in New Mexico, and Muhammad Ishtiaq reported for VOA's Urdu Service from Pakistan.