U.S. Secretary of Defense Leon Panetta said Thursday that intelligence about Syrian chemical weapons "raises serious concerns" that the regime of Bashar Assad may use them against the country's own citizens.

"The whole world is watching, the whole world is watching very closely," Panetta said. "And the president of the United States has made it very clear, there will be consequences — there will be consequences if the Assad regime makes the terrible mistake by using these chemical weapons on their own people."

His comments came a day after U.S. officials told NBC News that the Syrian military had loaded the precursor chemicals for sarin, a deadly nerve gas, into aerial bombs that could be dropped from dozens of fighter-bombers. The defense chief, who was speaking at a news conference at the Department of Veterans Affairs, would not elaborate on what the potential consequences would be. 

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A member of the regime in Damascus, however, dismissed the assertions Thursday, saying he feared the United States and other Western powers could be trying to find a "pretext for intervention" in Syria's civil war, Reuters reported.

Sarin is an extraordinarily lethal agent. Iraqi President Saddam Hussein's forces killed 5,000 Kurds with a single sarin attack on Halabja in 1988.

Assad's deputy foreign minister Faisal Maqdad said Thursday that they would never kill Syrians with chemical weapons, dismissing the Western intelligence reports as "theater."

"Syria stresses again, for the tenth, the hundredth time, that if we had such weapons, they would not be used against its people. We would not commit suicide," Maqdad said, according a Reuters report that cited his comments on Lebanon's Al Manar television, the voice of the pro-Assad Hezbollah movement.

"In fact, we fear a conspiracy ... by the United States and some European states, which might have supplied such weapons to terrorist organizations in Syria, in order to claim later that Syria is the one that used these weapons," he added.

"We fear there is a conspiracy to provide a pretext for any subsequent interventions in Syria by these countries that are increasing pressure on Syria," he said.

 

Panetta echos Obama 'red line' warning
"The intelligence we have raises serious concerns"  that Damascus was considering using chemical weapons, Panetta said Thursday.

"Without commenting on the specific intelligence ... we remain very concerned, very concerned that as the opposition advances, in particular on Damascus, that the regime might very well consider the use of chemical weapons." 

Obama and other NATO leaders have warned that using chemical weapons would cross a red line and have consequences, which they have not specified.

Four U.S. Senators on Thursday urged President Obama to send a strong message to Assad.

"We urge the President of the United States to make whatever military preparations are necessary to show Assad that the United States is fully willing and able to impose the consequences that he has spoken of in the event these weapons are used," said Sen. John McCain (R-Ariz), speaking first. "For deterrence to work it must be based on a credible threat."

He appeared with Sen. Joseph Lieberman (I-Conn.), Sen. Chris Coons (D-Del.) and Sen. Lindsay Graham (R-S.C.).

"We are all saying to President Obama, who has stated that there will be drastic consequences for Assad and his government if they use chemical and biological weapons, we’re with you," said Lieberman. "There’s strong support across Congress if the president takes the strong action that’s necessary to prevent a very, very — historically horrific — humanitarian disaster in Syria. 

There are limited options for military intervention by the United States in Syria. It has one of the most robust air defense systems in the world — supplied by key ally Russia — but one option could be sending cruise missiles to attack regime targets.

Germany's cabinet approved stationing Patriot anti-missile batteries on Turkey's border with Syria, a step requiring deployment of NATO troops that Syria fears could permit the imposition of a no-fly zone over its territory.

Slideshow: Syria uprising
Syria loads chemical weapons into bombs; military awaits Assad's order
Syria regime 'reeling, armed to the teeth' with chemical weapons
More weapons in Syria could trigger 'all-out war'

The 20-month-old battle between Assad and opposition forces has claimed more than 40,000 lives.

U.S. Secretary of State Hillary Clinton met in Dublin on Thursday with Russian Foreign Minister Sergei Lavrov and international Syria mediator Lakhdar Brahimi to try to restart a U.N. peace process for Syria. Prior to the meeting, she said she expected to raise the chemical weapons threat.

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Clinton has said that in addition to the possible use of chemical bombs by "an increasingly desperate" Assad, Washington was concerned about the government losing control of such weapons to extreme Islamist armed groups among the rebel forces.

U.S. officials said Washington was considering blacklisting Jabhat al-Nusra, an influential rebel group accused by other rebels of indiscriminate tactics that has advocated an Islamic state in Syria and is suspected to have ties to al-Qaida.

In other developments reported by Reuters:

• Syrian state TV said a\n explosion in front of the Damascus headquarters of the Syrian Arab Red Crescent killed at least one person on Thursday.
• Activists said the army pummeled several eastern suburbs of Damascus, where the rebels are dominant, with artillery and mortar fire. The suburbs have been cut off from the city's water and electricity for weeks, rebels say, accusing the government of collective punishment.
• Rebels say they have surrounded an air base two-and-a-half miles from the center of Damascus, a fresh sign the battle is closing in on the Syrian capital.
• Rebels said they were battling soldiers on the road to Damascus International Airport, 12 miles out of the capital, where several airlines have canceled flights due to security concerns.

Maqdad, in his interview on Thursday, argued that reports of such advances were untrue. "What is sad is that foreign countries believe these repeated rumors," he said. Rebel and state claims about the military situation cannot be verified independently. But residents inside the capital say the sound of shelling on the outskirts has become a constant backdrop. 

Reuters contributed to this report.

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With tensions between Israel and Iran running sky high over the latter's nuclear program, U.S. officials and military analysts are growing increasingly concerned that Israel will launch a multi-phase air and missile attack that could trigger waves of retaliatory missile strikes from Tehran.

Such a shootout could quickly spiral into a regional conflict that would potentially force the U.S. to intervene to protect its interests.

The emerging consensus among current and former U.S. officials and other experts interviewed by NBC News is that that an Israeli attack would be a multi-faceted assault on key Iranian nuclear installations, involving strikes by both warplanes and missiles. It could also include targeted attacks by Israeli special operations forces and possibly even the use of massive explosives-laden drones, they say.

The Iranian response to such an attack is uncertain, but many experts and officials believe it is likely to include retaliatory missile strikes. Iran has more missiles in its arsenal than Israel, according to some estimates, and has the capability of striking targets in most Israeli population centers.

"I think that it would strike Iran as a reasonable response, an eye for an eye," said Christopher J Ferrero, a professor of diplomacy at Seton Hall University in New Jersey and an expert on Middle East missile forces.

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He also said Iran would likely attack major cities with its Shahab 3 missiles, which he said are not as accurate as the Israeli missiles, but would be an effective "instrument of terror … that could certainly cause significant damage to heavily populated suburban and urban areas.

 

 

Israel possesses advanced anti-missile defenses, but those systems could be overwhelmed if Tehran launched large numbers of missiles, as Ferrero expects.

Given the immense difficulties in carrying out successful air strikes on the four key Iranian installations using its warplanes alone -- as laid out last week by the New York Times, U.S. officials say Israel would be likely to coordinate such airstrikes with waves of missiles. This would greatly increase the chances of penetrating fortifications that Iran has built to protect some of its key installations and overwhelm Iran's air defenses, said the former and current U.S. officials, who spoke on condition of anonymity.

"Two words:  Jericho missiles," said one former White House and Pentagon official, speaking on condition of anonymity, when asked how Israel would attack Iranian targets at great distances. "They are conventionally armed, have a very small CEP (circular error of probability, meaning they are highly accurate) and can be used in conjunction with a strike fighter operation."

Israel has as many as 100 Jericho ballistic missiles – both short- and medium-range – as well as submarine-launched cruise missiles, though the officials say they believe the latter are unlikely to be used. The short-range Jericho I missiles would be of no use in an attack on Iran, because the targets are far beyond its 300-mile range. However, the  medium-range Jericho II's are capable of  hitting targets as far as 900 miles away – or as far east as Tehran. Israel also tested a Jericho III intercontinental ballistic missile in 2008 and Israeli media have reported that it may have deployed one or more of the weapons, which would put all of Iran within reach.

The missiles would most likely be launched from the Hirbat Zekharyah missile range, midway between Israel and the Mediterranean Coast, according to "Critical Mass: the Dangerous Race for Superweapons in a Fragmenting World," by William E. Burrows and Robert Windrem, and various Israeli press reports.

Although designed to be part of Israel's nuclear deterrent force, the Jerichos can be equipped with high explosives as well as nuclear warheads. U.S. officials have said that an Israeli attack, if it happens, would be intended to surgically take out the nuclear facilities, not inflict the mass casualties that would result from a nuclear attack.

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Iran has no capability to defend against a missile strike, said Ferrero, the expert on Middle East missile arsenals.

"If the Jerichos are accurate enough to get to their targets, they will get to their targets," he said.

What Iran does have is hundreds of Shahab 3 medium range ballistic missiles, according to U.S. estimates. The Shahab 3 also has a range of roughly 900 miles.

Israel, possibly supplemented by U.S. shipborne anti-missile systems – the Aegis Standard Missile-2 -- could intercept and destroy some of the incoming Iranian missiles, said Ferrero. But the numbers favor Iran, he said.

"I believe that (the Iranians) have a sufficient inventory that they could overwhelm those missile defenses and still get enough missiles through to cause damage," he said.

The critical factor may be the number of  missile launchers in Iran's inventory, Ferrero said, because penetrating Israel's defenses would require numerous  missiles, but also enough launchers to be able to fire them off simultaneously. That number is a closely guarded secret, he said.

Additionally, U.S. intelligence estimates say Iran has supplied Hezbollah with more than 40,000 short-range rockets and missiles since 2006. However, U.S. officials are uncertain whether Hezbollah would follow Iranian orders, and risk Israeli retaliation or, if they did, how many they would fire.  The majority of the rockets and missiles are unguided.  Israel and the U.S. have worked on a short-range missile defense system called Iron Dome, but there are concerns that waves of attacks could overwhelm the system.

Also open to question in U.S. and Israeli military circles is whether an Israeli attack would meet its objective: setting back the Iranian nuclear program anywhere from two to five years.

U.S. officials say Israel would be likely to concentrate its attacks on four key Iranian nuclear complexes. Key facilities within those complexes – the Natanz and Fordo centrifuge facilities, both south of Tehran; the Arak research reactor, southwest of Tehran; and a uranium hexafloride production and research facility near the city of Isfahan – are protected by heavy fortifications, they said.

The Jerichos are stored in tunnels in limestone formations around Hirbat Zekharyah and rolled out for firing. They would likely be used as part of a one-two punch, the officials say. The first attack would be carried out by Israeli strike fighters and would be intended to breach the heavily fortified outer ceilings of the facilities. The second (and possibly even third) wave would be missile attacks aimed at destroying the facilities within, the officials said. 

Asked if Jerichos would have the accuracy and the explosive power to take out hardened bunkers or fortifications believed to be protecting Iran's most-sensitive underground nuclear facilities, a current U.S. official replied, "You would be surprised at their accuracy." The official added that the missiles' warheads would contain a special mix of explosives that could penetrate the Iranian defenses.

U.S. officials also say Israel may have learned the location of facilities that fabricate centrifuge components. These, too, could be targeted.

A 2010 book on the possibility of an Israeli attack laid out the difficulties Israel would face if it attempted to use only its strike fighters on those targets.

 "Attacks against the sites at Natanz, Isfahan and Arak alone would stretch Israel's capability and planners might be reluctant to enlarge the raid further," wrote authors Steven Simon and Dana H. Allin, in "The Sixth Crisis – Iran, Israel and the Rumors of War." Simon, then a fellow at the Council on Foreign Relations, now heads the Middle East Desk at the National Security Council.

The biggest problem is the fortification of the two centrifuge facilities. Simon and Allin describe the challenge using aircraft only.

"Natanz is the only one of the … likely targets that is largely underground, sheltered by up to 23 meters (75 feet) of soil and concrete," they wrote. "… Bombs used in a ‘burrowing' mode, however, could penetrate deeply enough to fragment the inner surface of the ceiling structures above the highly fragile centrifuge arrays and even precipitate the collapse of the entire structure."

But for the attack to have high odds of success, they argue, aircraft would have to drop additional bombs into the cavities created by the first bombs. That would require "time on target" -- a luxury that the Israeli jets at the outermost limits of their 1,100-mile range would likely not have. While they estimate the success rate of such a plan at "better than 70 percent," they call it "complicated and highly risky."

Another difficulty for attacking Israeli aircraft would be finding a route to the targets that could be flown covertly or with the tacit approval of Sunni Arab states, who are at least as frightened of an Iranian nuclear capability as the Israelis.

Simon and Allin (and others) have written that there are three "plausible routes" that Israeli warplanes would take to attack Iran: a northern approach, likely along the Syrian-Turkish border; a central path that would take them over Jordan and Iraq; and a southern route that would transit the lower end of Jordan, Saudi Arabia and Kuwait. The southern route is the most likely, U.S. officials suggest, because the Saudis and other Sunni-dominated Gulf states are eager for someone to take out the Iranian threat. They prefer the U.S. do it, but have reportedly shared intelligence on the Iranian program with the Israelis, if only on a limited basis, according to the U.S. officials.

No matter what route the fighter bombers take, they would use what one U.S. official described as "high-low, low-high" flight paths – flying high first to increase fuel efficiency, then low for most of the trip to evade radar, then climbing high again as the bombs are released in what is known as a "flip toss" from as far as 10 miles from the target.

The Israelis would be prepared to lose aircraft if necessary, the officials said.

Although Simon and Allin do not discuss adding a missile component, other experts, including many current and former U.S. officials, believe the Israelis already have made a decision to have them in the attack menu.

Missile attacks would be coordinated with fighter-bomber attacks (presumably, the Israelis' F-16, F-18 and extended-range F-15I Strike Eagle). The missiles would have to be launched so that warheads strike targets following the strike fighter attacks.  Because of the short flight time, minutes rather than hours in the case of the aircraft, the missile launch would almost certainly take place at the last possible moment to ensure the secrecy of the overall attack.

The Israelis are not planning to use their submarine-launched cruise missile force -- "not enough of them," one official said of the subs. (The Israelis have long had nuclear tipped sub-launched cruise missiles as part of their deterrent force.) 

Beyond the strike fighters and the missile force, U.S. officials suggest the Israelis could use two other "weapons" against Iran.

The first is special operations forces that would be secretly inserted into the country. At the least, they could be employed to illuminate aim points for laser-guided bunker-busting bombs. At the most, they could launch their own attacks on facilities, particularly those believed to contain enriched uranium.

The other is a new generation of large drones with wingspans approaching those of a Boeing 777  (almost 200 feet). Costing $30 million each, the Heron drones are capable of remaining airborne for 40 hours at a time and have a range of 4,600 miles. While they can be equipped with surveillance and electronic warfare equipment, some officials call them "strike drones," meaning they could be loaded with explosives and used to attack Iranian targets.

While the initial days of an Israeli-Iranian conflict would probably be bloody, most experts say that the open warfare would be expected to wind down within days or weeks, since neither side has the ability to occupy the other's territory or enough missiles to sustain attacks.

But that would bring with it its own set of problems, as the conflict would be likely to continue on a lower level, involving covert operations and terrorism.

"You could have a very nasty covert war emerge," said Ferrero.

Robert Windrem is a senior investigative producer for NBC News.

BEIJING – Wenzy Duan dreams about becoming a delegate to the United Nations.

“I know this [ambition] is pretty high,” said the 17-year old Beijing native.  “But I think I can give it a shot.” 

To prepare, Duan wants to study international relations at an American college – someplace like the University of Washington. “I hear [it] is good at social science," she said.

The University of Washington is one of approximately 10 U.S. universities Duan plans to apply to in the coming year with the help of an education consultant she hired last summer.

“I know that the scores is not the only thing that the university will consider whether you can get in or not,” said the high school senior.

Duan is not alone.  Today, China sends more of its students to America than any other country. During the 2010-11 academic year, 157,588 Chinese students were studying in the U.S. – an increase of 23 percent from the previous year, according to the Institute of International Education. 

The growing market of Chinese students wanting to go to the U.S. has created various cottage industries in China and the U.S. –  among them are education consultants who help students navigate the maze of college applications and "brokers" representing American universities who seek student candidates paying full tuition. But it's also fueled anxiety among American students and their parents about increased competition from abroad.

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Education consultants: the main cottage industry
“When [Chinese students] decide to come to the U.S. and study in the U.S. school, they have no idea,” said Steven Ma, president of ThinkTank Learning, the consulting group with which Duan is working.  "What do colleges in the U.S. look for anyway?  What do they want?  What type of students they want?  And that’s where we come in.”

ThinkTank Learning, based in Santa Clara, Calif., offers tutoring and college counseling.  Most of the students contracting its services have been Asian-American, but Ma said increasingly his firm began fielding calls from mainland Chinese families wanting their advice. 

Eventually ThinkTank Learning opened a branch in Shenzhen in 2009 and then in Beijing a year later.  It charges anywhere from $17,000 to almost $40,000 for tailored consultation packages lasting six to 12 months, dispensing advice on choosing the right schools, writing essays, or preparing for interviews.  

“They’ll just tell you when you need to get something done by what deadline and how do you prepare your application to the school’s standards,” said Julia Yin, Duan’s mother, a petroleum engineer who hails from Hunan province.  “Basically, everything is DIY [do it yourself.]"

Go West, Young Man (and Woman)
China sent its first student to an American college in 1850: A native of Guangdong Province named Yung Wing earned his degree from Yale University, paving the way for thousands more over the following century.

The flow of students from China to America dried up in the 1950s when the establishment of the People’s Republic of China gave way to tumult and isolation, and did not re-start until 1974 1978.

From then until just a few years ago, "It was almost all graduate students, most of them funded by the host universities through research assistantships or teaching assistantships," said Peggy Blumenthal, senior counselor to the president at the Institute of International Education (IIE).

Now, Chinese undergraduates drive the growth, particularly in the past two years.  At the start of the 2006-07 academic year, 9,955 Chinese undergrads were enrolled in U.S. schools. The following year, that figure jumped to 16,450.  By the 2010-11 academic year, 56,976 undergraduates made up a third of all Chinese students living in the U.S.

“What you’re seeing is the growth of the middle class of China who can really afford to send their kids to the U.S.,” said Blumenthal.  “The Chinese undergrads are all coming virtually self-funded.”

The fact that so many students pay their own way has not gone unnoticed.

"Foreign students spend about $21 billion a year in the U.S. in tuition and living expenses for them and their families,” said Charles Bennett, Minister-Counselor for Consular Affairs at the U.S. embassy in Beijing – where Ambassador Gary Locke has made among his top priorities the expansion of visa processing capacity in China.

“That’s a very large sum of money for U.S. academic institutions,” continued Bennett, especially as so many face shrinking endowments or reduced state funding.

The Chinese comprise at least 21 percent of all international students newly enrolled in American schools, which means that they and their families contribute roughly $4 billion to the American economy, according to the U.S. Department of Commerce.

Edging out American students in America?
Recent reports, however, have suggested mainland Chinese students and their ability to pay full tuition are costing American students placement in American colleges. A bankrupt state school system in California – one of the most popular destinations for Chinese students – has meant that its well-regarded schools are seeing record enrollments from out-of-state and international students. 

For the 2010-11 academic year, California welcomed the most international students – 96,535. And for the tenth year in a row the University of Southern California was the leading host U.S. institution for overseas students, enrolling 8,615, according to the IIE.

But the IIE argues adding mainland Chinese students is helpful for diversity.  “Most Americans will not study abroad. On the other hand, their careers will be global,” observed Blumenthal.  “They need to learn how to interact with professionals from other countries, and many of them will be from China.  There are very few industries or business not affected by China.”

Moreover, at the graduate level, Chinese students aren’t competing against American students for a seat in the classroom, according to Blumenthal.  “There still aren’t enough Americans in the pipeline wanting to get graduate training in the fields of science, technology, engineering, and math,” she said.

But detractors note other challenges have surfaced as a result of so many Chinese students going to U.S. schools.  Among them is whether some applicants from the mainland are cheating their way into admissions by falsifying their academic records or achievements. 

One consulting company in Beijing that works U.S. universities, Zinch China, says 90 percent of Chinese undergraduates submit false recommendation letters for their U.S. college applications and that 70 percent enlist someone else to write their essays.

The dishonesty works the other way, too.  A growing number of “education brokers,” who work on behalf of U.S. institutions to solicit Chinese students, have led to misrepresentations and predatory fees, according to a revealing report from Bloomberg News. Some agents promise admission to top-flight schools, charge exorbitant fees, in some instances including a portion of scholarship funds, and students can end up at schools that are a far cry from the "dream schools" they hope to attend.  

Can China produce innovative thinkers?
The desire among Chinese students to seek an American college degree has grown stronger over the years owing to a number of factors.

Above everything else, there is the fierce competition for gaining admissions to a preeminent Chinese university. The selection process is decided solely by the gaokao, an annual national college entrance examination that lasts nine grueling hours over two to three days.

This past year, more than 9 million students across China took the gaokao.  And believe it or not, that number has been declining since 2008 as more students opt out of the gaokao and sign up for exams like the TOEFL (Test of English as a Foreign Language) and the SAT (Scholastic Aptitude Test), both of which are generally prerequisites for applying to any U.S. college or university.

A lively debate is growing about whether China’s education system can produce innovative thinkers who can enable the country to lead – not just catch up with or follow in the footsteps of industrialized economies like the U.S. or Britain. Such concerns triggered a widespread discussion online when Steve Jobs died earlier this year.

“The students here are not as robotic as Americans think,” said Gene Hwang, a 27-year-old Taiwanese-American, who has been working in China for ThinkTank Learning for almost two years.  “But they are held back by some of the systems in schools, which emphasize rote memorization….  We work with them on [developing] critical thinking.”

Broadening those horizons
“When I get into America, I can get [a liberal] education [that] could open my mind,” said Zhang Yuqi, a soft-spoken but intense 17-year-old high school senior.

He’s been working with a ThinkTank Learning consultant for three months, reviewing which schools to apply to and working on his essays.  A possible math major, he has his eye on Carnegie-Mellon and Emory where he hopes to find a climate that differs from his elite Beijing high school, which he says has too many “planned activities.”

Duan wants to study in the U.S., because “they accept all different kinds of different ideas.  You can dream about anything,” she said.  “In America, I can experience more…maybe all kinds of things I will never experience in China.”

For high school junior Dolly Luo, it's simply about getting the best education.  “The U.S. has the most well-developed college education," said the 16-year-old Beijing native who loves Harry Potter and dreams about attending an Ivy League college.

Her parents have similar faith in the U.S. college experience.

“She will have more opportunities, and it will broaden her horizons,” said William Luo.  In fact, Dolly’s father had harbored his own U.S. scholarly ambitions, but he didn’t have the financial resources to enable him to pursue his graduate studies in America.

“I hope when Dolly goes abroad and she learns American values or Western values that she can absorb the Western education – the good parts: the culture, the education,” continued Luo.  “In China, we would need that.” 

EDINBURG, Texas – While flying an afternoon patrol along the twists and turns of the Rio Grande, Lt. Johnny Prince, a veteran pilot for the Texas Department of Public Safety, spotted something suspicious: "Look here, we got a raft, a raft right here." 

Below him, in the middle of the river which separates Mexico from the United States was a group of men frantically paddling back to the southern riverbank, their attempt to reach the American side thwarted by the helicopter patrol.

Prince said he suspected the men were a team of drug cartel scouts who were planning to search the U.S. side of the river to make sure there were no law enforcement officers nearby.  If they determined the area was clear, he explained, they would then signal others to sneak a load of narcotics across the river in a raft.

Mike Avila, the helicopter's tactical flight officer, said that this was happening near an area nicknamed "Smugglers' Alley," because of all the illicit activity here.  Well-worn trails and a narrowing of the river have made this area a favorite for Mexican drug traffickers.

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‘That car's loaded to the gills’
Earlier that same day, Prince and Avila found themselves flying inland in hot pursuit of two vehicles –a car and a truck –loaded with Mexican marijuana.  As the vehicles sped through city streets on the American side of the river, Avila trained the helicopter’s high-powered camera on the fleeing smugglers and Prince called out their locations by radio to pursuing troopers on the ground.

One of the drivers sped along the wrong side of the road, then he raced through an intersection, almost striking two cars with his pickup truck.  "Oh no, oh no," groaned Prince.  Avila described another close call as the driver raced through a school zone before crashing into a building: "He nearly struck two school buses."

In both cases, the drivers – a man and a woman – were apprehended and troopers seized loads of marijuana from both their vehicles. Even from the sky, the pilots could see that one of the cars was carrying a lot of drug bundles.  "That car's loaded to the gills," said Prince. 

Increased aggression along a ‘porous’ border
For the helicopter teams, chasing smugglers along the Rio Grande in South Texas is virtually a daily occurrence. Pilots say they've seen the Mexican traffickers pushing larger amounts of illicit drugs into the United States over the last few years and have watched them become more menacing toward law enforcement officers and U.S. citizens.

"I've been working along the border for 14 years and in those 14 years I've seen the level of aggression increase exponentially.  The sheer volume of narcotics that's being pumped into our border has risen," said Capt. Stacy Holland, of the Texas Department of Public Safety Aircraft Section.

It's not unusual, Holland said, for smugglers to take only a couple of minutes to move more than a ton of marijuana across the river, up the U.S. side of the riverbank and into a vehicle which then heads north. "Our border is very open, our border is very porous," he said.

The pilots said they are convinced traffickers are much more likely now than they were a few years ago to confront U.S. law enforcement officials.  "We have video of them carrying AK-47's and side arms during these operations and they are not afraid to use them," said Holland. 

While flying in his helicopter, Prince has more than once been eye to eye with smugglers on the ground upset with his presence above.  "I've seen guns pointed at me, long guns.  I've seen rocks thrown at us.  One of the things they do is use sling shots with ball bearings in them," he said.  "A ball bearing with a good slingshot can do damage to this helicopter and that's been done."

Another serious concern is for the safety of Texas troopers and U.S. Border Patrol agents who have to tangle with the traffickers on the ground.  A particularly dangerous scenario involves agents coming upon a large group of smugglers loading a car with illegal drugs on the U.S. side of the Rio Grande. 

"Usually there's only one or two officers that first arrive at the particular vehicle on the river and they are encountering 15 or 20 cartel members," said Prince.  "On the other side, you will see another 10 to 15 cartel members, and if you see them armed they are going to be trying to cover the guys on the U.S. side."

Splashdowns
A highly unusual technique used by Mexican smugglers to elude capture by American authorities involves them driving trucks loaded with drugs into the waters of the Rio Grande.  It happens after Border Patrol agents or Texas troopers spot a drug-laden vehicle on the U.S. side of the river and give chase. 

If the smugglers can't elude their pursuers – either by speeding up or by throwing spikes into the road to flatten the tires of the officers behind they – they will then head back to the same spot along the river where traffickers brought the drugs ashore after floating them across from Mexico.

"If the loads get compromised, they will drive around in the United States, in Texas here, until they get their recovery teams set up on the river, to return the drugs back to Mexico," said Prince. 

The Texas Department of Public Safety has shot numerous helicopter videos of Mexican smugglers paddling over to the American side of the river to await the arrival of the truck racing toward them.  When the truck reaches the riverbank, it keeps going – right into the water. 

"Bam! All units, we have a splashdown, a splashdown in the river," a pilot on one of the videos can be heard transmitting on the radio. 

Before the truck sinks, the driver climbs out through the window and the recovery teams move quickly to save as much of the drug load as possible, throwing the tightly-wrapped bales into rafts. 

"Ok, we've got rafts in the river, a bunch of people on the U.S. side; that thing is loaded," said a pilot watching from above in one video.  "Suspects are in the water, trying to unload the vehicle," said another pilot hovering over a different scene.

As soon as the rafts are filled with off-loaded drugs, the smugglers paddle back to the Mexican side of the river where they are safe from arrest by American authorities.  Sometimes, the traffickers are so brazen they will make obscene hand gestures toward U.S. agents watching from across the river, or from above in helicopters.

The agents' only recourse at that moment is to notify Mexican authorities and hope they arrive in time to apprehend the smugglers.  Or, they can hope to catch the loads of drugs next time, when inevitably they are floated back across the Rio Grande during another smuggling attempt – sometimes on the very same day the drugs are recovered after a splashdown.

No end in sight
The pilots who routinely fly along the Rio Grande said they see nothing that would suggest there is any let up in the amount of smuggling along the river.  In fact, they predict increased violence on U.S. soil.

"You get a lot more home invasions, a lot of crook on crook crimes, a lot of kidnappings, the cartels coming over here maybe trying to collect money and then retreating back over to Mexico," said Holland. 

Texas newspapers have reported recently on cartel shoot-outs in Houston and McAllen, the wounding of a deputy, the arrests of alleged cartel leaders in the Rio Grande Valley and the seizure of cartel property in the U.S.—along with the almost daily news of major drug seizures.

Statements by the Obama Administration and by some local officials that the U.S.-Mexican border is safer than ever are derided by many of the pilots.

"Our citizens in our border towns are caught in the crossfire, and I mean that in the most literal sense sometimes," said Holland.  "It's important that our citizens, not only in the state (of Texas), but in the United States are aware of how porous our border is and what the threats are, and could be."

More coverage from Mark Potter: Along Mexican border, US ranchers say they live in fear

See more of Mark Potter's reporting on NBC's Nightly News with Brian Williams Tuesday evening.