HIDALGO, Texas - Locked in a capsule the size of a phone booth suspended 20 feet over a cabbage field in south Texas, a National Guard soldier spends a Sunday night with a gun attached to his hip while watching an orange grove through infrared lenses.

Stationing 1,200 National Guard soldiers at the border for one year costs $110 million.

That same night, to the west, an ominous whistle slices through the silence of dawn as a mile-long train is stopped in the middle of a bridge over the Rio Grande. In a ritual repeated every night, an officer of U.S. Customs and Border Protection unlocks a door, a railroad patrolman slides open the heavy doors, and they point their flashlight beams to inspect under, above and in the middle of the load of cars and electronics before it goes through an X-ray machine in search of hidden people or drugs.

Putting rail freight through an X-ray machine costs $1.75 million.

That night, in southern Arizona, a guard sees something strange in a truck with a trailer loaded with coal and requests a more detailed examination. Dogs trained to smell drugs begin to bark, and the guard finds 8,000 pounds of marijuana in several trucks.

The annual salary of a Customs and Border Protection agent averages $75,000. A drug-sniffing dog costs $4,500.

At a time when Congress is debating how to fund the border and governors are demanding more assistance, The Associated Press has investigated what it costs taxpayers to secure the border between Mexico and the United States.


The price has not been publicized so far. But AP, using White House budgets, reports obtained through requests covered under the Freedom of Information Act and congressional transcripts, came up with the total amount: $90 billion in 10 years.

For taxpayers who pay this amount, the result has been bittersweet: fewer illegal immigrants, but little impact on terrorism. And it certainly has not stopped the supply of drugs.

The terrorists who perpetrated the attacks of Sept. 11, 2001, did not come from Mexico, but the attacks led politicians to review border security. Ten days later, President George W. Bush announced a new Department of Homeland Security, with tasks that include the security of the country's porous southern border.

Over the next 10 years, annual spending on the border has tripled while the United States built an unprecedented network spanning 1,900 miles along the border with Mexico: 165 X-ray machines for trucks and trains; more than 650 miles of heavy-duty fences and concrete walls; double the amount of agents along the entire stretch; and a small fleet of Predator drones. In addition, remote surveillance cameras, thermal imaging devices and partially buried ground sensors that sound an alarm in the central office when someone steps on them in the desert.


"The obligation to secure our borders implies the responsibility to make it as cost-effective as possible, and we recognize there's no single solution to meet the security needs on our border," said Homeland Security spokesman Matthew Chandler.

Over the years, the objectives of security measures at the border have changed.

Initial concerns that terrorists could filter out weapons from Mexico to the United States were overshadowed by concerns about the violent drug cartels that kill people along the Rio Grande. As the American economy declined, preventing illegal immigrants from crossing north in search of work became the center of attention.

"Border security is no longer about just responding to Sept. 11. It became a very important part of the debate on immigration," said Jena Baker McNeill, an analyst for national security policy at The Heritage Foundation, a right-wing research institute in Washington.

In fact, detaining immigrants at the border has become a bargaining tool with Congress for the last two governments: fences and guards in exchange for immigration reform, Baker McNeill said.

The increase in resources has dramatically reduced illegal immigration. Ten years ago, border agents caught 1.6 million illegal immigrants in a year. Last year only 463,000 were caught. The decline is attributed in part to the U.S. recession, which reduced jobs here, but it is also a sign, according to federal authorities, that fewer people are trying to cross the border illegally.


Spending, however, has not helped stem the flow of illegal drugs. Last year, border guards seized the record figures of 254,000 pounds of cocaine, 3.6 million pounds of marijuana and 4,200 pounds of heroin. In response, the heads of the Mexican cartels just sent over more: trains loaded with marijuana and cocaine hidden in the bumpers and dashboards or heroin hidden in the shoes of young men.

It is estimated that some 660,000 pounds of cocaine, 44,000 pounds of heroin and 220,000 pounds of methamphetamine circulate on U.S. streets in any given year, according to the Office of National Drug Control Policy. A fraction of that amount was seized at the border, a small cost for the drug traffickers operating in Mexico; they will earn about $25 billion this year from U.S. sales.

Last month, a Department of Justice study that reviewed the total cost of illicit drug use in the U.S. and included studies on the cost of diseases, federal crime statistics and economic models, arrived at an annual figure of $193 billion.

"It is going to be impossible to seal the border. You can never stop anything 100%. As long as there's a market, while profits are made, someone will be willing to take risks to make sure that the product gets to the other side," said Rep. Silvestre Reyes of Texas, a former director of the Border Patrol.

Despite the increasing violence around the corner - the dead in Mexico's fight against cartels surpasses 35,000 - the Obama administration reported that populations on the U.S. side of the border enjoy relative peace. Terrorists do not usually cross the border into the United States, officials say.

However, Rep. Michael McCaul, R-Texas, warned against complacency.

"There is disagreement over the definition of overwhelming violence and the magnitude of that violence, but there should be no disagreement about the threat we face and what will happen if this government continues to minimize the threat," he said. "So what should we do? First, we must leave our trenches and address this growing threat. If we do not, the cartels will eventually try to take over our cities."

If Homeland Security Secretary Janet Napolitano could talk to Mexican drug lords, this is what she says she would say, "Don't even think about bringing your violence and your tactics to this side of the border. You will be greeted with an overwhelming response."

And if she could talk to aspiring illegal immigrants, she would say:

"There are more Border Patrol agents than ever at the border. There are more customs officials. There is more technology. Don't bet everything on the cartels or criminal organizations because the probability of getting caught and the consequences of doing so are greater than ever."

By 2012, the record budget for border security in Obama's administration proposes an additional $242 million to pay for high-tech surveillance towers and mobile detection devices along the border, $229 million to increase the salary of Border Patrol agents and $184 million to identify and deport criminal aliens in state prisons and local jails. This in addition to about $14 million to support the current infrastructure.

Over the years, budget allocations tell the story of a changing border policy.

In 2002, when security checks after Sept. 11 were four-hour waits at the border, the Bush administration sought $380 million to build a cutting-edge system for entry and exit visas.

In 2006, the federal government put an end to the immigration policy of "catch and release" in which local police had been releasing illegal immigrants if they had not committed a crime locally. Now they turn them over to the feds and they are judged for violating immigration law. Taxpayers in that year paid $327 million for 4,000 new beds to detain suspected illegal immigrants until they could be legally prosecuted.

In January, the government withdrew Obama SBInet, a project to install a "virtual" high-tech border fence that would cost taxpayers nearly $1 billion but did little to improve security.

"From the beginning, SBInet was an unrealistic approach," said Connecticut Sen. Joe Lieberman, chairman of the Homeland Security and Governmental Affairs. "The department's decision to use technology based on the specific security needs of each segment of the border is a much more prudent focus, and I hope it will be more cost-effective."