As President Bush was bumping along the banks of the Rio Grande last week with the United States Border Patrol, an American unmanned aircraft was apparently tracking a top Al Qaeda member to an abandoned house in remote Pakistan.
While details are emerging as to whether the terrorist network's operation manager was killed in a drone attack, Mr. Bush is increasingly convinced that the military technology should be used more widely within the US as well - to spot illegal border-crossers.
So far, the US Border Patrol has one unmanned aerial vehicle, or UAV, and it is equipped solely with a camera for surveillance. But the president says he wants to outfit the border with several more.
"Slowly but surely, technology is being employed up and down the border, and that's a key part of our strategy," Bush said from El Paso, Texas, last week.
With the numbers illegally crossing the US border with Mexico remaining high, estimated at 1 million people each year, the Border Patrol has increasingly turned to technology to help secure the 2,000-mile stretch. Electronic sensors, night-vision goggles, and high-tech cameras are all well established. But the UAV, known as the Predator B, is just making its border debut - and some remain unconvinced that its whopping $14 million price tag is worth it.
The Border Patrol's sector in Tucson, Ariz., unveiled the first drone on Sept. 29 after some testing earlier in the year. Todd Faser, Border Patrol spokesman, says more than 1,000 illegal immigrants and over 400 pounds of illegal narcotics have been caught with its help.
The UAV will be operated by a Border Patrol agent acting as the pilot, who sits in a cockpit-like control station at Fort Huachuca, Ariz. The aircraft is flown by remote control and equipped with an electro-optic sensor that can send back images, day or night.
It can reach speeds of up to 253 miles per hour and usually hovers between 15,000 and 20,000 feet above ground while working. When an illegal entry is spotted, a Border Patrol agent sitting next to the pilot can then relay the information to other agents in the field.
The idea is that a UAV can cover far more territory than can a Border Patrol agent in an SUV. Mr. Faser calls them "force multipliers" that help agents gain control of some of the remotest parts of the border.
"Our primary mission is to prevent terrorists and their weapons from entering our country, and to do that we need the right combination of personnel, technology, and infrastructure," he says. "You can't just have a fence and no Border Patrol agents to stop illegal immigration. You can't just have 50,000 agents and no technology to stop illegal immigration. You need the proper mix."
But T.J. Bonner, president of the National Border Patrol Council, says all technology has its limits.
Electronic sensors, for instance, can't tell whether a human being or an animal has tripped them. Cameras can, but they don't have the ability to follow somebody. UAVs can locate and track a group, but they aren't as agile as manned aircraft - and are far more costly.
"You can put a lot of boots on the ground for $14 million," says Mr. Bonner, whose union advocates more helicopters instead of drones.
The US military has been using UAVs far longer than the Border Patrol. In Afghanistan and Iraq, for instance, 20 types of drones flying more than 100,000 hours have been providing intelligence and shooting missiles.
"They were designed for a different purpose, and they work very well for that purpose," says Bonner. "But they are not as suitable for our purposes. We don't get our pilots shot at."
He believes Bush's call for more drones along the border is misguided and says more emphasis should be placed on making sure that employers don't hire illegal immigrants.
Still, technology can help agents do their job better, says Mark Krikorian, executive director of the Center for Immigration Studies in Washington - but it's not a magic bullet.
On any given shift, there is still only one Border Patrol agent per mile - even after a decade of staffing buildup. "Technology is a tool, but it's only a tool. The personnel has to be adequate and the policy objectives appropriate," says Mr. Krikorian. "I would rather see better policy and less technology."
• Material from Reuters was used in this report.