If the reports are correct, it's not known why Assad would do that, since he's blamed al-Qaida for suicide bombings against his embattled regime as a popular uprising moves into its 11th month.

It may be a message to the West, warning the Americans, British and French in particular they face retaliation if they provide the rebels with military support.

It could also be a gesture toward the Muslim Brotherhood, the most organized of Syria's opposition groups.

But if Nasr's on the loose again, trouble is likely on the way.

The influential al-Qaida icon, better known by his nom de guerre of Abu Musab al-Suri, has a $5 million U.S. bounty on his head. He allegedly inspired the July 7, 2005, triple suicide bombing of London's transit system in which four British-born jihadists killed 52 people and wounded more than 700.

Nasr, who trained as a mechanical engineer, is also wanted in Spain in connection with the March 11, 2004, bomb blitz that hit four commuter trains in Madrid, killing 191 people.

In 2003, he was indicted by a Spanish judge for building sleeper terrorist cells in the country. He's also been linked to a Spanish cell that helped the 9/11 hijackers prepare for the carnage in the United States.

The Syrian-born Nasr, who is married to a Spanish woman and holds dual Syrian and Spanish nationality, was arrested Oct. 31, 2005, by Pakistani police after a gun battle in the southwestern city of Quetta. He was handed over to the CIA several months later.

Nasr vanished into the legal limbo of the CIA's secret renditions and its global network of secret prisons and became a "ghost prisoner." There were reports he was in Afghanistan, Syria and India, although there was no confirmation of his whereabouts.

It seems the Americans quietly passed Nasr on to Syrian intelligence.

This may have been done in hopes of gaining access, through Syrian torture, to his intimate knowledge of al-Qaida's inner workings or perhaps in exchange for favors from Damascus, which has played hot and cold with al-Qaida over the years.

Unconfirmed reports said that after he fell into Syrian hands, Nasr was held in the top security prison in Aleppo, the city of his birth.

In August 2011, the Shumoukh al-Islam online forum posted a note that indicated Nasr was then being held in the headquarters of Syrian General Intelligence in the Kfar Sousa district of Damascus, a high-security zone where several of Syria's many intelligence services have offices.

In December, Sooryoon.net, a Syrian opposition Web site, claimed he'd been released.

Nasr was involved in the Muslim Brotherhood's war against Assad's father, Hafez, during the 1980s.

He fled Syria after the regime smashed the Sunni fundamentalists in February 1982, razing much of the city of Hama and slaughtering up to 30,000 people.

There has been no confirmation from Syria that Nasr has been freed. His whereabouts are unknown. It's unlikely, however, that he's still in Syria.

What makes him so important is his writings as Abu Musab al-Suri.

His masterwork, an encyclopedic, 1,600-page volume entitled "The Call for Global Islamic Resistance" has become the blueprint for jihad and draws heavily on the lessons of past conflicts.

"Al-Suri is emblematic of the rise of a new generation of jihadist strategic study writers, who are still a tiny minority but whose writings are informed by pragmatism, presented in a rational-secular style and emphasize a willingness to put political effectiveness before religious dogmas," the Jamestown Foundation, a Washington think tank, wrote in 2007.

Nasr had long advocated the decentralization of al-Qaida, which is how the jihadist movement has emerged since 9/11.

He didn't rate Osama bin Laden very highly and opposed his 9/11 terrorist spectacular, arguing it would trigger massive retaliation that would cripple the jihadist network, which is what happened.

Before his capture, he produced a series of lengthy tracts on jihadist ideology, training and objectives, particularly locally organized operations.

Western counter-terrorism officials say these treatises were a template for major al-Qaida attacks in Casablanca in 2003, Madrid in 2004 and London in 2005.

]]> Thu, 09 FEB 2012 09:07:26 AEST Phnom Penh, Cambodia (UPI) Feb 6, 2012 - Defense lawyers continued to attack the Document Center of Cambodia, claiming its archival material presented to the U.N.-sanctioned genocide tribunal is biased.

Four former senior Khmer Rouge leaders remain on trial for their part in the brief but brutal Khmer Rouge government of 1970s.

The Document Center was started in 1995 as a field office for Yale University's Cambodian Genocide Program with U.S. State Department funding. In 1997 it became an independent non-government organization with funding from several countries, including the United States, Australia, Japan and Canada.

The trial of the four Khmer Rouge leaders continues after the tribunal, the Supreme Court Chamber of the Extraordinary Chambers in the Courts of Cambodia, turned down the appeal of another Khmer Rouge member, Duch.

Also known as Kaing Guek Eav, Duch is a former math teacher and Christian convert who ran the feared Tuol Sleng prison, also known as S-21, in Phnom Penh under the Khmer Rouge government.

Duch became the first high-ranking official to be sentenced by the Chamber in Cambodia's highly political genocide trials. In 2010 he was sentence to 35 years in prison, less five years for time already spent in custody, and appealed the sentence last March.

On top of turning down Duch's appeal, the Chamber increased the 69-year-old's sentence to life in prison.

The Chamber said on its Web Site that is had considered the high number of deaths for which Duch is responsible -- a minimum 12,272 lives -- along with the extended period over which the crimes were committed -- more than three years.

These facts "undoubtedly place this case among the gravest before international criminal tribunals," the Chamber said.

The fact that Duch wasn't "on the top of the command chain in the regime" doesn't mean he should get a lighter sentence.

"There is no rule that dictates reserving the highest penalty for perpetrators at the top of the chain of command," the Chamber said.

Duch's increased sentence last week was met with cheers as well as relief by victims and their families -- fearful it might have been reduced.

However, many more Cambodians await the outcome of the ongoing trial four former Khmer Rouge cadres who were "top of the chain of command."

Ieng Sary, 86, was the regime's minister of foreign affairs and Nuon Chea, 85, was the Khmer Rouge's main ideologist.

Chea was "Brother Number Two" to "Brother Number One," Pol Pot, who died in 1998. Pot fled the country after an invading Vietnamese army toppled the regime in 1979.

Khieu Samphan, 80, was the president.

Ieng Thirith, 79, wife of Ieng Sary and Khmer Rouge social affairs minister, has been absent from proceedings because of suspected advanced Alzheimer's disease.

Their lawyers have focused on the work of the Document Center.

Jasper Pauw, a lawyer representing Chea, questioned the veracity of material collated under the Document Center's Accountability Project and handed to the prosecution, The Phnom Penh Post newspaper said.

He also asked why it was necessary for the center to, in its own words, "illuminate chains of command" during the time of Democratic Kampuchea, as the Khmer Rouge called Cambodia.

"Because we want to know who actually killed two million Cambodians," center Director Youk Chhang said. "We want to know what happened in our history."

Pauw asked if, through the Accountability Project, the center was trying to implicate senior Khmer Rouge leaders in "alleged atrocities."

Chhang said the Accountability Project's purpose was to "gather historical information for the court in order to find the culprits who committed crimes during that period," the Post reported.

Arthur Vercken, defense lawyer for Samphan, asked Chhang about the potential fabrication of documents, including one deemed by the center to have be a fake, the Post report said.

Chhang said it would be "virtually impossible" to fabricate 1 million documents.

]]> Thu, 09 FEB 2012 09:07:26 AEST Washington DC (SPX) Feb 06, 2012 - Thanks to lightning-fast software from the Department of Homeland Security's Science and Technology Directorate (DHS S and T), if a truck bomb was discovered in Lower Manhattan we will now be able to predict the likely damage patterns in the surrounding areas, and prioritize the first responders' activities long before the bomb's acoustic shockwave ricocheted out at the speed of sound.

It's called the Urban Blast Tool (UBT), and it stores a table of pre-calculated pressure loads that would course down Lower Manhattan's canyons after a range of blasts, from a humble car bomb to a massive truck bomb packing many times the payload of the Oklahoma City bomb.

For decades, such predictions stumped the fastest computers. Now, answers can be generated on a humble PC. The Urban Blast Tool was developed for S and T by Weidlinger Associates of New York.

Using a dead-accurate city model already known, the software determines the damage building by building. Lower Manhattan has already been modeled and, pending Congressional funding, it will be joined by Midtown Manhattan and then parts of Los Angeles, Chicago, Washington, and Boston.

Each street in an urban area is a labyrinth of crevices, corners, and contours, where the course of a shockwave never could run smooth. These irregular features make a tough challenge tougher. When a shockwave strikes a building, some of its energy is absorbed; the remainder glances off, as a reflection.

More often than not, the reflection rejoins the shockwave, making the wave more focused...and more violent. Blocks away, buildings and people will feel the punch. At 10 blocks, the wave may be packing only 1 pound per square inch (1 psi). But that's enough force to shatter windows and buckle walls.

After 9/11, scientists tried to model how a blast's shockwave would travel down specific urban canyons: If a bomb this size is set off at that spot, will the tower over there progressively fail? Will its beams hang low? Will occupants be able to evacuate safely? Safe evacuation is the most immediate concern.

These questions went unanswered because blast simulations weren't reliable. Beams, waves, and reflections trade energy in an intricate dance, especially within the bulls-eye of the blast, where pressures are extreme. Supercomputers running computational fluid dynamics can calculate the pressures as a shockwave radiates, but this can take weeks. In order to evacuate the most vulnerable buildings immediately, responders must size up the danger in minutes once a possible vehicle bomb is discovered.

In 2008, S and T began to look beyond the eye of the blast. After all, a blast would deliver much of its wrath blocks away and at lower pressures the force and effects could be calculated in mere seconds.

Why not use computational fluid dynamics to pre-calculate the initial blast loads in fine detail, and store those results? Then, if an actual bomb explodes, responders and planners can call up these known values and crunch them through modeling software to warn responders of which structures may soon fail.

Lower Manhattan comprises some 100 city blocks and hundreds of tall buildings. Their makeup is no mystery: Google Earth and Google Streets know each streetscape, from every angle. Indeed, a vibrant community of Googlers has re-created a 3D model of each building, plaza, and park. Using these models as building blocks, Weidlinger built a virtual replica, fashioned from 1s and 0s.

To give the shockwave calculations a running start, Weidlinger drew on physics-based analytical software codes the company had developed for the Department of Defense (DOD).

American soldiers in Baghdad were facing truck bombs daily. Earlier, to better understand that threat, DOD had conducted tests for which Weidlinger had modeled blast pressures and structural damage. The company applied this experience to the Urban Blast Tool.

The first code for the model predicts a blast's shock physics in all three dimensions, from its opening thunder through its closing whimper. Weidlinger determined how a blast's force would rise and decay as the wall of heated air fanned out, confronting specific buildings in its path.

A second code analyzes a building's strength and predicts distant damage, right down to the floor joists. Using codes, a blast wave propagation and structural response could be modeled for a typical sample of the area buildings, over a range of blast threats. Together, these models form a library-a cheat sheet-that makes quick work of calculating downstream damage. And it's done in seconds.

Since the software's interface was built on Google Earth, it has a familiar look and feel. That familiarity can be a life-saver after a bomb explodes, and responders, racing to the scene, may have just minutes to determine which buildings may tumble.

With the Urban Blast Tool software comes another important piece of software: the Emergency Evacuation, Rescue and Recovery Model (EERR).

This companion software can evaluate the odds that a column will fail, and its emergency systems suffer damage, no matter whether a building is made of steel frames, reinforced-concrete frames, or flat plates. The Urban Blast Tool and EERR are the crown jewels of a suite of S and T-funded applications designed to help cities protect infrastructure from blasts.

Says architect Mila Kennett, the S and T program manager who oversaw the software's development: "We will offer the entire suite at no charge to emergency planners, DHS agencies, and credentialed architects, engineers, and building owners. Using our new software, they'll be able to identify safer evacuation routes, design more-blast resistant buildings, and fortify older buildings."

Like other S and T-funded technologies, the Urban Blast Tool is merely one weapon in a responder's toolkit. But on the urban battlefield, where threats require a layered defense, each layer counts.

"We can't thwart every bomb," says Kennett, "But here at S and T, we always looking for innovative solutions to protect more lives."

]]> Thu, 09 FEB 2012 09:07:26 AEST Manila (AFP) Feb 3, 2012 - Philippine troops battled Muslim extremists on a remote southern island on Friday where a day earlier three of Southeast Asia's top terror suspects were killed in a US-backed air strike, the army said.

Soldiers who approached the bombed area on the outskirts of a small village on Jolo island after the raid faced dogged resistance from surviving militants, regional military spokesman Lieutenant Colonel Randolph Cabangbang said.

"There is intermittent fire, the area is not yet secured," Cabangbang told GMA television in a telephone interview.

The troops had moved into the scene of the strike in an effort to retrieve the bodies of the three senior militants who were killed, as well as to take on the others who survived Thursday's aerial assault.

The military said 15 members of the Al Qaeda-linked Abu Sayyaf and Jemaah Islamiyah (JI) organisations were killed in the air raid, which followed months of surveillance on the sparsely populated and isolated hinterland of Jolo.

Cabangbang gave no indication as to the scale of Friday's fighting, but military chiefs said on Thursday that about 30 militants were at the scene when the bombings began.

The military said it had targeted, and killed, Malaysian Zulkifli bin Abdul Hir, alias Marwan, one of the United States' most-wanted terror suspects with a $5 million bounty on his head from the US government.

Zulkifli was one of JI's top leaders and a bomb-making expert who had been hiding out in the southern Philippines since 2003, according to the US State Department.

Also reported killed was Singaporean Mohammad Ali, alias Muawiyah, another JI leader who had been hiding in the Philippines since the group killed 202 people in a series of bomb attacks on the Indonesian island of Bali in 2002.

The third senior militant reported killed was Filipino Abu Pula, also known as Doctor Abu or Umbra Jumdail, one of the core leaders of the Abu Sayyaf that is blamed for the worst terrorist attacks in the Philippines.

The military claimed the killings dealt a major blow to the capabilities of the two terror groups, particularly their ability to strike in the Philippines.

Philippine armed forces spokesman Colonel Arnufo Burgos said on Thursday that the US military provided intelligence that helped in the success on the bombing raid.

A rotating force of 600 US Special Forces has been stationed in the southern Philippines since 2002 to help train local troops in how to combat Islamic militants.

The US forces are only allowed to advise the Filipino soldiers and are banned from playing a combat role.

]]> Thu, 09 FEB 2012 09:07:26 AEST Bogota (AFP) Feb 2, 2012 - In a city known for violence, authorities have launched a campaign to get guns off the street.

Police chose a slum in Ciudad Bolivar perched on a barren mountain in the outskirts of Bogota as the first place to enforce a new ordinance restricting the carrying of weapons.

Police officers stopped cars, vans and buses to check its occupants, most of whom agree with the law.

"At least I know there is no thief on the bus and that they are not going to attack me," Jose Mauricio Moreno, a 35-year-old salesman, told AFP.

Bogota, with a population of more than 7 million people, recorded 1,632 homicides last year. City administration figures show 62.3% of them were committed with firearms.

Bogota's new mayor, Gustavo Petro, a 51-year-old former leftist guerrilla, announced just after taking office that carrying weapons is now restricted in public places and on the streets.

The ordinance does not apply to public security forces, private guards found throughout the capital, and guards of diplomats or ministers.

But city officials aim to "discourage the use of arms" and raise awareness among citizens about the "futility and danger of carrying a firearm," Petro said when he launched a campaign called, "To arm or to love. Yes to citizen disarmament."

However, the ordinance has provoked strong criticism from Petro's opponents, who say the mayor is undermining civil liberties.

Some security experts doubt the ban will lower the crime rate, saying nearly all homicides in Bogota are committed with illegal weapons.

Alfredo Rangel, an analyst at the Security and Democracy Foundation, said the measure has popular and media appeal but will have only a "marginal effect" on crime.

"It has nothing to do with crime," Rangel told AFP. "People who own legal firearms are not the ones who go rob banks."

In Medellin, Colombia's second largest city with 2.3 million residents, a gun ban has been in effect for three years but the homicide rate rose 7% in 2011, Rangel said.

The homicide rate in Bogota in 2011 was 21.5 per 100,000, well below major Colombian cities of Cali (77.9 per 100,000) and Medellin (70.3 per 100,000). Both cities are former drug cartel strongholds where criminal gangs still proliferate.

Colonel Alvaro Bermudez, Ciudad Bolivar's police commander, agreed the gun ban "will not change the world" but it might stop "someone who is going to have a beer, who would pull a gun after a few drinks in a small scuffle."

Violations of the law allow police to permanently confiscate guns, among other penalties.

Supporters of the ordinance include Alirio Lopez, a priest who for 14 years has promoted youth disarmament in his parish.

The gun ban "is on the right track. What matters is a change of mentality, that people realize that a gun does not make you stronger," said the priest, who is known popularly as "Father Tolerance."

]]> Thu, 09 FEB 2012 09:07:26 AEST Manila (AFP) Feb 3, 2012 - The Philippine military said Friday it had not been able to obtain proof that it killed three of Southeast Asia's most-wanted terror suspects, but insisted the trio had died in a US-backed airstrike.

Troops were sent to the isolated jungle area where Thursday's bombing took place on the remote southern island of Jolo, but they found no bodies, armed forces spokesman Lieutenant Colonel Arnulfo Burgos told reporters in Manila.

Burgos said the three senior leaders from the Al Qaeda-linked Abu Sayyaf and Jemaah Islamiyah (JI) networks, as well as 12 slain junior figures, had been taken away by fellow militants and quickly buried as per Muslim custom.

"After the airstrike, the bodies were taken immediately," Burgos said.

However he said the military was certain the top trio had been killed, based on intelligence "assets".

"Yes, its an A-1 (information). We have something but we cannot divulge all the other information because its an operational (secret)," he said.

The highest-profile militant reported slain was Malaysian Zulkifli bin Abdul Hir, alias Marwan, one of the United States' most-wanted terror suspects with a $5 million bounty on his head from the US government.

Zulkifli was one of JI's top leaders and a bomb-making expert who had been hiding out in the southern Philippines since 2003, according to the US State Department.

Also reported killed was Singaporean Mohammad Ali, alias Muawiyah, another JI leader who had been hiding in the Philippines since the group killed 202 people in a series of bomb attacks on the Indonesian island of Bali in 2002.

The third senior militant reported killed was Filipino Abu Pula, also known as Doctor Abu or Umbra Jumdail, one of the core leaders of the Abu Sayyaf that is blamed for the worst terrorist attacks in the Philippines.

There was particular focus Friday on whether Philippine authorities could provide proof that the high-value trio had been slain because of previous incorrect claims of killing senior militants.

In 2009, the military said it had killed senior Abu Sayyaf commander Albader Parad but he gave a radio interview a few days later to prove he was still alive.

In 2001, then-president Gloria Arroyo said the Abu Sayyaf's top leader, Khadaffy Janjalani, had been killed. He later went on television to prove he was alive.

Burgos said Friday that security forces were confident of finding the bodies of the slain leaders, or at least pieces that would allow DNA confirmation.

But efforts to search the remote jungle area where the airstrike took place were hampered by gunfire from the surviving extremists, said regional military spokesman Lieutenant Colonel Randloph Cabangbang.

"There is occasional gunfire. They fire from a distance, just to disrupt our operations," he said.

The US military helped in Thursday's attack by providing intelligence support, military officials said.

A rotating force of 600 US Special Forces has been stationed in the southern Philippines since 2002 to help train local troops in how to combat Islamic militants.

The US forces are only allowed to advise the Filipino soldiers and are banned from playing a combat role.

Spokespeople at the US embassy in Manila declined to comment on Thursday's attack, referring all questions to the Philippine military.

]]> Thu, 09 FEB 2012 09:07:26 AEST Sanaa, Yemen (UPI) Feb 1, 2012 - U.S. airstrikes in Yemen that reportedly killed four al-Qaida commanders Tuesday came hard on the heels of a U.S. Navy SEAL team's Jan. 25 rescue of two Western hostages in Somalia, across the Gulf of Aden.

These U.S. strikes underline how the Americans are escalating covert operations against two Islamist groups in the region -- al-Qaida in the Arabian Peninsula and Somalia's al-Shabaab, which are deemed serious threats to the United States.

Tuesday's attacks in southern Yemen were among the biggest carried out by the Americans in the country at the southern tip of the Arabian Peninsula since airstrikes began there in November 2002 when a drone killed a key jihadist leader.

This is because the attacks, at least three of them, targeted AQAP leaders as part of U.S. President Barack Obama's military doctrine of hitting terrorist organizations with relentless covert operations by Special Forces and the CIA rather than large number of conventional forces.

Among those reported killed in airstrikes by a mix of fighter-bombers and missile-firing unmanned aerial vehicles was Abdel-Monem al-Fathani, a veteran jihadist. Tribal leaders said he was killed with several other al-Qaida members when their two-vehicle convoy east of Lawdar in southern Abyan province was blasted by an unmanned aerial vehicle in a pre-dawn strike.

Fathani allegedly was involved in the suicide bombing of the U.S. Navy destroyer USS Cole Oct. 12, 2000, in Aden harbor in southern Yemen. That attack killed 17 U.S. sailors.

He was also reputedly involved in the March 6, 2002, attack on the 157,000-ton French tanker Limburg off Yemen. In both cases, the bombers rammed explosives-packed small boats into the vessels.

All told, 12-15 AQAP fighters were killed in the recent airstrikes.

These were focused on jihadists operating in southern Yemen, where AQAP and its regional affiliate, Absar al-Sharia, or the Army of Islamic Law, have in recent weeks seized several towns in Abyan and neighboring Shabwa provinces in an offensive that has seriously undermined the crisis-ridden government in Sanaa.

The jihadists have taken advantage of political turmoil in Yemen that has pitted opponents of longtime President Ali Abdullah Saleh against his supporters. The military has split in a yearlong conflict in which hundreds of Yemenis have been killed.

Saleh, who narrowly survived an assassination attempt last summer, has agreed to step down but the political situation remains confused and violence continues.

The conflict impaired the government efforts to confront AQAP, which has become one of the most aggressive and effective al-Qaida affiliates and seeks to establish an Islamic caliphate in Yemen.

U.S. officials say AQAP seeks to join force with al-Shabaab in Somalia to control the strategic Bab el-Mandeb strait at the southern end of the Red Sea, the maritime link between the Mediterranean and the Indian Ocean.

The Abyan towns of Zinjibar, the provincial capital, Al Koud, Ja'ar, Shaqra and Rawdah are held by the jihadists, along with Azzan in Shabwa.

On Jan. 16, AQAP forces led by Tareq al-Dahab, brother-in-law of U.S.-born AQAP ideologue and operational commander Anwar al-Awlaki, seized the town of Rada'a, population 60,000, in Bayhdah province just 100 miles south of Sanaa.

The Americans allege that Awlaki was behind two failed attempts to attack the continental United States, including the Christmas Day 2009 plot to blow up a Northwest Airlines jet over Detroit.

Awlaki, who held U.S. citizenship, was assassinated Sept. 30 in a UAV strike in al-Jawf province. His 16-year-old son, Abdul Rahman, was killed in drone attack Oct. 14.

The Long War Journal Web site, which monitors U.S. operations, says the Americans are known to have carried out 11 airstrikes since May 2011, when Obama intensified the campaign against AQAP. That tally included Tuesday's attacks.

Since December 2009, there have been at least 17 U.S. air or Tomahawk cruise missile strikes against AQAP targets.

One of the most significant developments in recent months is that it's clear the U.S. forces engaged in Yemen, currently headed by the hefty CIA contingent, are operating with far more accurate intelligence than was the case before last year.

On June 3, AQAP's top commanders were hit in one strike and the group confirmed that two important chieftains -- Ali Abdullah Naji al-Harithi and Ammar Abadah Nasser al-Waeli -- were killed.

]]> Thu, 09 FEB 2012 09:07:26 AEST Champaign IL (SPX) Feb 02, 2012 - Anyone who has flown on a commercial airline since 2001 is well aware of increasingly strict measures at airport security checkpoints. A study by Illinois researchers demonstrates that intensive screening of all passengers actually makes the system less secure by overtaxing security resources.

University of Illinois computer science and mathematics professor Sheldon H. Jacobson, in collaboration with Adrian J. Lee at the Central Illinois Technology and Education Research Institute, explored the benefit of matching passenger risk with security assets. The pair detailed their work in the journal Transportation Science.

"A natural tendency, when limited information is available about from where the next threat will come, is to overestimate the overall risk in the system," Jacobson said.

"This actually makes the system less secure by over-allocating security resources to those in the system that are low on the risk scale relative to others in the system."

When overestimating the population risk, a larger proportion of high-risk passengers are designated for too little screening while a larger proportion of low-risk passengers are subjected to too much screening. With security resources devoted to the many low-risk passengers, those resources are less able to identify or address high-risk passengers. Nevertheless, current policies favor broad screening.

"One hundred percent checked baggage screening and full-body scanning of all passengers is the antithesis of a risk-based system," Jacobson said.

"It treats all passengers and their baggage as high-risk threats. The cost of such a system is prohibitive, and it makes the air system more vulnerable to successful attacks by sub-optimally allocating security assets."

In an effort to address this problem, the Transportation Security Administration (TSA) introduced a pre-screening program in 2011, available to select passengers on a trial basis.

Jacobson's previous work has indicated that resources could be more effectively invested if the lowest-risk segments of the population - frequent travelers, for instance - could pass through security with less scrutiny since they are "known" to the system.

A challenge with implementing such a system is accurately assessing the risk of each passenger and using such information appropriately. In the new study, Jacobson and Lee developed three algorithms dealing with risk uncertainty in the passenger population.

Then, they ran simulations to demonstrate how their algorithms, applied to a risk-based screening method, could estimate risk in the overall passenger population - instead of focusing on each individual passenger - and how errors in this estimation procedure can be mitigated to reduce the risk to the overall system.

They found that risk-based screening, such as the TSA's new Pre-Check program, increases the overall expected security. Rating a passenger's risk relative to the entire flying population allows more resources to be devoted to passengers with a high risk relative to the passenger population.

The paper also discusses scenarios of how terrorists may attempt to thwart the security system - for example, blending in with a high-risk crowd so as not to stand out - and provides insights into how risk-based systems can be designed to mitigate the impact of such activities.

"The TSA's move toward a risk-based system is designed to more accurately match security assets with threats to the air system," Jacobson said.

"The ideal situation is to create a system that screens passengers commensurate with their risk. Since we know that very few people are a threat to the system, relative risk rather than absolute risk provides valuable information."

The National Science Foundation and the U.S. Air Force Office of Scientific Research supported this work.

]]> Thu, 09 FEB 2012 09:07:26 AEST Algiers, Algeria (UPI) Jan 31, 2012 - U.S. officials say Algerian intelligence foiled an al-Qaida plot to mount suicide attacks against U.S. and European ships in the Mediterranean at a time when the jihadists are driving to expand operations in North Africa.

The Algerian intelligence service, Direction de la Securite Interieure -- DSI -- caught the plot in its early stages and arrested three suspected members of al-Qaida's North African affiliate, al-Qaida in the Islamic Maghreb.

The Algerian daily newspaper Echorouk broke the story a week ago. U.S. officials said they knew of the plot but the Algerians made the arrests.

Echorouk reported that the men had purchased a boat that they reportedly planned to pack with explosives and ram into a ship in the western Mediterranean. The plot, as outlined by the newspaper, bore a striking resemblance to tactics used by al-Qaida's Yemeni branch when it badly damaged the U.S. Navy destroyer USS Cole in Aden harbor Oct. 12, 2000, by ramming it with a small boat packed with explosives.

That attack killed 17 U.S. sailors and wounded dozens more.

An earlier attack using similar tactics against another U.S. destroyer, USS The Sullivans, failed when the attacking boat foundered.

Al-Qaida struck again with a seaborne suicide attack against the 157,000-ton French tanker Limburg off Yemen's coast as it sailed from the Persian Gulf to Malaysia Oct. 6, 2002. The vessel was holed and one crewman killed but it continued its voyage.

In May 2002, Moroccan authorities arrested three Saudi members of al-Qaida who were convicted of planning seaborne suicide attacks on U.S. and British warships in the Strait of Gibraltar.

Moroccan police said in April 2007 they were hunting a jihadist group supposedly planning similar attacks on ships, although no such strikes took place.

In the Algerian crackdown, it wasn't clear whether the Americans endorsed Algiers' decision to round up the trio of suspects, rather than wait to see how the plot developed and possibly track down other militants. However, relations between the Americans and Algeria's security establishment have been strained for some time.

Algeria, the regional military heavyweight, considers itself the leading player in the counterinsurgency campaign against AQIM, which is based in Algeria and is the backbone of the jihadist movement in North Africa.

Until September 2001, Washington and Algiers, which had fought a vicious war against Islamist militants, were greatly at odds, particularly over the Algerians' ferocious tactics to crush the insurgents. These included battle-hardened Arab veterans of the 1979-89 war in Afghanistan against the Soviet army, from which al-Qaida emerged.

After the Americans also found themselves fighting jihadists, led by al-Qaida, they sought a rapprochement with Algiers. The Algerians remain deeply suspicious of the United States.

The current rift centers on the refusal of Gen. Ahmed Gaid Salah, the Algerian military's chief of staff, to allow the United States to deploy U.S. Air Force and CIA surveillance drones in Algerian air space.

The Intelligence Online web site quoted a French general that the U.S.-Algeria friction was "a big black hole." The bottom line is that the Algerians don't want U.S. or other Western forces on their soil.

The Algerians set up a joint intelligence center at their air base at Tamanrasset, deep in the Sahara Desert, in 2010 with neighboring Mauritania, Niger and Mali.

The Americans have been using a Moroccan air force base in the Sahara to conduct counter-terrorism surveillance operations using drones.

The U.S. Africa Command is running a dozen counterinsurgency training missions, mostly involving Special Forces units, in several North African countries.

The French, who once ruled North Africa, are conducting similar operations. But they've also deployed combat forces that have carried out raids, primarily with forces from Mali, on jihadist bases in the region over the last two years. AQIM currently holds several French hostages.

Meantime, the fallout from the 2011 war in Libya continues to plague the region.

Islamist fighters and rogue mercenaries, including many North Africans hired by Moammar Gadhafi to defend his ill-fated regime, along with large amounts of plundered weapons, are worsening the security situation in Algeria, Morocco, Tunisia and further south in Mali, Niger and Mauritania.

"AQIM is solidly entrenched across the region and has now entered the arena of interstate politics," Oxford Analytica reported in a Jan. 25 analysis.

]]> Thu, 09 FEB 2012 09:07:26 AEST Lagos (AFP) Jan 28, 2012 - Nigerian troops on Saturday killed 11 fighters from the Islamist sect Boko Haram during a shootout in the northeastern city of Maiduguri, a spokesman said.

"Today, in an exchange of fire during a cordon-and-search operation conducted by the JTF, 11 Boko Haram members were killed," Lieutenant Colonel Hassan Mohammed told AFP by telephone, referring to the army's Joint Task Force unit.

Mohammed said no casualties were suffered by the JTF, a specialised squad set up last year to crack down on Boko Haram, a shadowy group that is blamed for the deaths of more than 200 people already this year.

Maiduguri, the capital of Borno state, was placed under a state of emergency on December 31 by President Goodluck Jonathan along with other parts of the country hard hit by Boko Haram's attacks.

The city is seen as Boko Haram's base.

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