Waseem Naikzad / AFP - Getty Images

Afghan security force sit on top of a military vehicle in Laghman province Wednesday. US Defense Secretary Leon Panetta said on Tuesday he was very concerned about the rise in insider attacks on US and NATO troops, and the impact they are having on cooperation with Afghan allies.

News analysis

KABUL, Afghanistan – A group of U.S. Marines in Helmand province was invited to dinner by a local police commander and his men late last week.  A little after midnight, under the dark Afghan sky, the Marines left the police compound and were shot in the back as they walked away. Three were killed.

Last week, seven Americans lost their lives after Afghans they were working with turned their weapons on them.

The military is now designating these incidents in which Afghan troops turn on coalition counterparts as "insider attacks," (they were once called "green-on-blue" incidents) to account for the non-security personnel also involved in the assaults. 

Insider attacks are now at the highest level they have been since the start of the war.

Three US special ops troops killed, Afghan officials say 

In 2007 and 2008 there were four such attacks and four deaths.

So far this year, there have already been 29 incidents in which Afghans turned their weapons on their coalition partners, killing 37.  That’s compared with a total of 21 incidents, in which 35 were killed, in all of 2011. 

The spike has startled many and brought calls to find the catalyst for the deadly problem.

Jose Cabezas / AFP - Getty Images

Members of the Afghan National Army are helped by a US soldier as they participate in a map reading training session at Narizah base in Narizah, Khost Province, on August 12, 2012.

Who or what is to blame? 
One group that would seem like the obvious culprit is the Taliban. They have claimed to infiltrate the Afghan National Security Forces, consisting of both the military and police, to help kill NATO troops from the inside. 

Last year, the group called on more Afghans in uniform to join their cause and turn their weapons on the “foreign invaders” because of their access and proximity. 

NATO does not deny some of the attacks have been from Taliban insurgency infiltration – but they attribute the trend to more than that.

Seven American troops killed in Afghan chopper crash

“There was infiltration; that is correct, we can acknowledge that,” said Brig. Gen. Gunter Katz, spokesman for the NATO-led International Security Assistance Force based in Kabul.  However, he said most of the attacks could be blamed on more basic warfare issues.

“The main reasons for those green on blue incidents are personal grievances, stress situations and what we call battle fatigue,” Katz said.

Slideshow: Afghanistan: Nation at a crossroads

Hoshang Hashimi / AP

More than ten years after the beginning of the war, Afghanistan faces external pressure to reform as well as ongoing internal conflicts.

Launch slideshow

He attributes about 10 percent of the insider attacks to Taliban infiltration, and blames the remaining 90 percent on individual motives.

However, U.S. Defense Secretary Leon Panetta acknowledged the Taliban are somewhat to blame for the attack earlier this week.

“The reality is, the Taliban has not been able to regain any territory lost, so they’re resorting to these kinds of attacks to create havoc,” Panetta told reporters in a Pentagon briefing Tuesday, according to Stars and Stripes.

Panetta later said there is “no one source” responsible for the attacks, and that there are several reasons why Afghan forces would turn on coalition troops.

Cultural divide 
A former commander of the Afghan Border Police, Gen. Aminullah Amarkhil, blames the attacks on a disrespect of the Afghan culture by foreign forces.

“The main reason for these attacks is that the foreign troops have on many occasions humiliated the Afghan culture and religion,” Amarkhil said.  “They’ve entered Afghan homes without permission, killed innocent civilians, they’ve bombarded wedding parties, they’ve entered our mosques with dogs, burned the Holy Quran. All of these are the factors that have contributed to the Afghan army or police being infiltrated by people who have been humiliated by the foreign troops.”

The Afghan general admitted it is not just the fault of NATO, adding that the insider attacks are also because of the weakness in the Afghan National Security Forces’ recruitment system.

“We don’t have a proper procedure for recruitment in our army or police. There are people in the Afghan army who have come from Pakistan and have made Afghan identity cards, " said Amarkhil, explaining that loyalties can be divided.

Training on Afghan culture
Amarkhil believes more should be done to show respect for the Afghan culture and religion by the foreign forces. And ISAF says they are doing just that.

“We continue to improve this process further and further in order to teach our guys [about] ‘what is Afghan culture.’  What can be done, what must not be done,” Katz said.  “We are very serious about that.”

In the meantime, ISAF has implemented force protection measures to help prevent more insider attacks.  Katz would not elaborate on what those measures are.

“We permanently assess the environment our soldiers are working in and assess if the current force protection measures are still in accordance to our assessment. And if not, we change them.”

But Katz says that these incidents, although tragic, are isolated.

“We had a very bad week last week,” he says.  But he believes for the most part there is trust between the Afghan and international forces.

“The more we fight together, the more we trust each other.”

NBC’s Fazl Ahad contributed to this report.

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Updated at 8:11 a.m. ET: A suicide car bomber struck early Monday at the gates of Jalalabad airport in eastern Afghanistan, killing nine people in a large blast, officials said.

Among the dead were six civilians, two airport guards and one soldier, Mohammad said. Another six people were wounded, he said.

An AP photographer saw at least four destroyed cars at the gates of the airport.

The Afghan Taliban claimed responsibility for the suicide attack, that they also say killed a number of U.S. soldiers and members of the Afghan interior ministry, a spokesman told NBC News.

"Our suicide bomber carried out suicide attack at a time when the U.S. troops opened the main entrance for change of the night time shift at the airport. Besides American soldiers, a number of Afghanistan interior ministry personnel working (with) the U.S. troops were also killed in the attack," the Taliban spokesman Zabihullah Mujahid told NBC News.

He said it was revenge of the desecration of holy Quran allegedly by U.S. forces at the Bagram airbase.

But NATO forces spokesman Capt. Justin Brockhoff said that no international forces were killed in the early morning attack and that the installation was not breached by the blast.

Escalating violence
The blast comes a day after demonstrators hurled grenades at a U.S. base in northern Afghanistan, and a gun battle left two Afghans dead and seven NATO troops injured Sunday in the escalating crisis over the burning of Muslim holy books at an American airfield.

More than 30 people have been killed, including four U.S. troops, in six days of unrest. Still, the top U.S. diplomat in Afghanistan said the violence would not change Washington's course.

"Tensions are running very high here, and I think we need to let things calm down, return to a more normal atmosphere, and then get on with business," Ambassador Ryan Crocker told CNN's "State of the Union."

"This is not the time to decide that we're done here," he said. "We have got to redouble our efforts. We've got to create a situation in which al-Qaida is not coming back."

Story: Eight US soldiers wounded in Afghan NATO base attack

The attack on the base came a day after two U.S. military advisers — a lieutenant colonel and a major — were found dead after being shot in the head in their office at the Interior Ministry in the heart of the capital. The building is one of the city's most heavily guarded buildings, and the slayings raised doubts about safety as coalition troops continue their withdrawal.

The incident prompted NATO, Britain and France to recall hundreds of international advisers from all Afghan ministries in the capital. The advisers are key to helping improve governance and preparing the country's security forces to take on more responsibility.

A manhunt was under way for the main suspect in the shooting — an Afghan man who worked as a driver for an office on the same floor as the advisers who were killed, Interior Ministry spokesman Sediq Sediqi said. He did not provide further details about the suspect or his possible motive.

Story: Afghan officer sought in connection with US slayings

The Taliban claimed that the shooter was one of their sympathizers and that an accomplice had helped him get into the compound to kill the Americans in retaliation for the Quran burnings.

Afghanistan's defense and interior ministers were to visit Washington this week, but they called off the trip to consult with other Afghan officials and religious leaders on how to stop the violence, Pentagon press secretary George Little said. The Afghan officials had planned to meet with Defense Secretary Leon Panetta and Joint Chiefs Chairman Gen. Martin Dempsey.

The protesters in Kunduz province in the north threw hand grenades to express their anger at the way some Qurans and other Islamic texts were disposed of in a burn pit last week at Bagram Air Field, north of Kabul.

The Associated Press contributed to this report.

Slideshow: Protests erupt over Quran burning

Parwiz / Reuters

Angry afghans attacked U.S. bases after reports of Quran desecration.

Launch slideshow

Sabah Arar / AFP - Getty Images

Iraq's former premier Iyad Allawi during a press conference in Baghdad in October, 2009.

A leading Iraqi politician has accused the country's prime minister of acting like Saddam Hussein in trying to silence opposition, saying he risks provoking a new fightback against dictatorship.

Iyad Allawi -- a former prime minister who leads the Sunni-backed Iraqiya bloc -- also claimed the United States had pulled out its troops "without completing the job they should have finished."

Allawi said that the current premier, Nuri al-Maliki, had used fabricated confessions to demand the arrest of the country's Sunni Muslim vice president, Tareq al-Hashemi.

Al-Hashemi, who has taken refuge in Iraq's autonomous Kurdish region, denies allegations he ordered bombings and shootings against his opponents. The move against him, on the very day U.S. troops left the country, threatens to upset a balance among Shiite, Sunni and Kurdish factions.

Speaking to Reuters two days after the final departure of the U.S. forces that ended Saddam's Sunni-dominated rule, Allawi called for international efforts to prevent al-Maliki, who is a Shiite, from provoking renewed sectarian warfare of the kind that killed tens of thousands in the years after Saddam fell in 2003.

"This is terrifying, to bring fabricated confessions," Allawi said shortly before leaving the Jordanian capital Amman to return to Iraq. "It reminds me personally of what Saddam Hussein used to do where he would accuse his political opponents of being terrorists and conspirators."

• Arrest order for Sunni VP in Iraq raises tensions

"We fear the return of dictatorship by this authoritarian way of governing. It's the latest in a build-up of atrocities, arrests and intimidation that has been going on a wide scale," said Allawi, who comes from the Shiite Muslim majority but who has drawn support heavily from disaffected Sunnis.

As prime minister for 10 months under U.S. occupation in 2004 and 2005, Allawi was accused of revealing an authoritarian streak himself. He later led the Iraqiya bloc to first place in last year's parliamentary election but ended up joining a coalition headed by al-Maliki, who retained the premiership.

• For 'the Sheik,' US pullout is cause for alarm

He said he would now try to unseat the prime minister in the legislature: "We have to make a move to bring about stability to the country by trying to find a substitute to Maliki through parliament," said Allawi, who repeated allegations that Shiite Iran is seeking control in Iraq now that U.S. forces have left.

"Maliki has crossed all red lines and Iraq is now facing a very, very serious and very difficult situation," he said.

'Very heart of democracy'
"We are watching events unfolding which are aimed at the very heart of democracy and stability," he added. "The Americans have pulled out without completing the job they should have finished. We have warned them that we don't have a political process which is inclusive of all Iraqis and we don't have a full-blown state in Iraq."

"We want to resolve issues between Iraqis in a peaceful way and we want to bring stability. Iraqis should fill the vacuum, rather than anybody else," Allawi said, in a reference to his view Iran is intent on filling a vacuum left by U.S. troops.

Iraq sits on a sectarian, Sunni-Shiite faultline that is generating conflict throughout the region, notably between Iran and Sunni-ruled Arab states like Saudi Arabia. While the overthrow of Saddam in Iraq bolstered Shiites, the uprising against Iran's Syrian ally President Bashar al-Assad could lead to power in Damascus shifting toward Syria's Sunni majority.

"The rise of sectarianism is already there," Allawi said. "We are witnessing the beginning of it and the influences of what is happening in the region is only adding fuel to the fire. My fear is that the Iraqi people will lose faith in the political process and sectarianism will prevail.

"Unless the international community and the region get involved and unless sense prevails, Iraq is heading towards a very big conflict."

Also Tuesday, al-Hashemi told a televised news conference that he has not committed any "sin" against Iraq and also described the charges as "fabricated." He accused al-Maliki of being behind a plot to smear him and declared that efforts at national reconciliation had been blown apart.

"I'm shocked by all these things," al-Hashemi told reporters in the northern city of Irbil. "I swear to God that al-Hashemi didn't commit any sin or do anything wrong against any Iraqi either today or tomorrow and this is my pledge to God."

He said the arrest warrant was a campaign to "embarrass" him. He blamed al-Maliki, although he did not say specifically what he believed the Shiite premier had done.

"Al-Maliki is behind the whole issue. The country is in the hands of al-Maliki. All the efforts that have been exerted to reach national reconciliation and to unite Iraq are now gone. So yes, I blame al-Maliki," he said.

The Iraqi prime minister effectively runs the Interior Ministry, where the charges originated.

Reuters and The Associated Press contributed to this report.

Updated at 8:46 a.m. ET

KHABARI CROSSING, Kuwait -- The last American troops crossed the border from Iraq into Kuwait early Sunday, ending the U.S. military presence there after nearly nine years.

As the last convoy left Iraq at daybreak Sunday, soldiers whooped, bumped fists and embraced each other in a burst of joy and relief, The Associated Press reported.

NBC News' Richard Engel tweeted from the border: "The gate to #iraq is closed. Soldier just told me, 'that's it, the war is over.'"

The final column of around 100 mostly MRAP armored vehicles carrying 500 U.S. troops trundled through the night along an empty highway, across the southern Iraq desert to the Kuwaiti border.

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After a ceremony Thursday in Baghdad formally marking the end of the war, the timing and all other details of the departure of the last convoy were kept under tight secrecy due to security concerns. The low-key end to the war was just another reminder of how dangerous Iraq remains, even though violence is lower now than at any other time since the 2003 invasion. 

The 210-mile trip from a base in southern Iraq took about five hours.

"I just can't wait to call my wife and kids and let them know I am safe," Sgt. First Class Rodolfo Ruiz said as the border came into sight. Soon afterward, he told his men the mission was over: "Hey guys, you made it."

NBC's Richard Engel answers your questions about Iraq

Pentagon Press Secretary George Little tweeted Sunday that Defense Secretary Leon Panetta "approved the order officially ending the Iraq war" at 6:59 a.m. ET.

The Iraq war began on March 20, 2003, at a time when national defense was a top priority for Americans still shocked by the Sept. 11, 2001, terrorist attacks. It continued with the invasion and ouster of Saddam Hussein, then ground through years of war against an insurgency that left tens of thousands dead.

Among those dead were nearly 4,500 Americans, and the war cost $800 billion from the U.S. Treasury. The question of whether it was worth it all is yet unanswered.

"It's good to see this thing coming to a close. I was here when it started," Staff Sgt. Christian Schultz said just before leaving Contingency Operating Base Adder, 185 miles south of Baghdad, for the border. "I saw a lot of good changes, a lot of progress, and a lot of bad things too."

Maya Alleruzzo / AP

Army soldiers from 3rd Brigade, 1st Cavalry Division, based at Fort Hood, Texas, inspect their body armor at Camp Adder during final preparations for the last American convoy to leave Iraq.

For President Barack Obama, the military pullout is the fulfilment of an election promise to bring troops home from a conflict inherited from his predecessor that tainted America's standing worldwide.

For Iraqis, it brings a sense of sovereignty but fuels worries their country may slide once again into the kind of sectarian violence that killed thousands of people at its peak in 2006-2007.

Prime Minister Nouri al-Maliki's Shiite-led government still struggles with a delicate power-sharing arrangement between Shiite, Kurdish and Sunni parties, leaving Iraq vulnerable to meddling by Sunni Arab nations and Shiite Iran.

PhotoBlog: Troops move out

The intensity of violence and suicide bombings has subsided for now. But a stubborn Sunni Islamist insurgency and rival Shiite militias remain a threat, carrying out almost daily attacks.

Iraq says its forces can contain the violence but they lack capabilities in areas such as air defense and intelligence gathering. A deal for several thousand U.S. troops to stay on as trainers fell apart over the sensitive issue of legal immunity.

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For many Iraqis security remains a worry -- but no more than jobs and getting access to power in a country whose national grid provides only a few hours of electricity a day.

"We don't think about America... We think about electricity, jobs, our oil, our daily problems," said Abbas Jaber, a government employee in Baghdad. "They left chaos."

Payments to sheikhs
After Obama announced in October that troops would come home by the end of the year as scheduled, the number of U.S. military bases was whittled down quickly as hundreds of troops and trucks carrying equipment headed south to the Kuwaiti border.

U.S. forces, which had ended combat missions in 2010, paid $100,000 a month to tribal sheikhs to secure different parts of highways leading south to reduce the risk of roadside bombings and attacks.

The conflict by the numbers

At the height of the war, more than 170,000 U.S. troops were in Iraq at more than 500 bases. By Saturday, there were fewer than 3,000 troops, and one base.

At COB Adder, as dusk fell before the departure of the last convoy, one group of soldiers slapped barbecue sauce on slabs of ribs brought in from Kuwait and laid them on grills alongside hot dogs and sausages.

Shannon Stapleton / Reuters

U.S. Air Force Senior Airman Janna Less, center, 23, smiles as she sits on the last Air Force flight out of Ali Air Base near Nasiriyah, en route to Kuwait on Saturday.

The last troops flicked on the lights studding their MRAP vehicles and stacked flak jackets and helmets in neat piles, ready for the final departure for Kuwait and then home.

"A good chunk of me is happy to leave. I spent 31 months in this country," said Sgt. Steven Schirmer, 25, after three tours of Iraq since 2007. "It almost seems I can have a life now, though I know I am probably going to Afghanistan in 2013. Once these wars end I wonder what I will end up doing."

Remembering the last slain American

When the convoy crossed the border into Kuwait around 7:45 a.m. local time, the atmosphere was subdued inside one of the vehicles. Along the road, a small group of Iraqi soldiers waved to the departing American troops.

"My heart goes out to the Iraqis," said Warrant Officer John Jewell, acknowledging the challenges ahead. "The innocent always pay the bill."

'Smooth sailing'
Soldiers standing just inside the crossing on the Kuwaiti side of the border waved and snapped photos as the final trucks rumbled over.

"I'm pretty excited," said Sgt. Ashley Vorhees. "I'm out of Iraq. It's all smooth sailing from here."

Vote: How would you describe the war in Iraq?

Spc. Brittany Hampton joked that no one was going to believe her back home when she told them she was in the very last of the 110 vehicles in the convoy to exit.

"But we really truly were the last soldiers in Iraq. So it's pretty awesome," she said.

"It's just an honor to be able to serve your country and say that you helped close out the war in Iraq," added Spc. Jesse Jones, a 23-year-old who volunteered to be in the last convoy. "Not a lot of people can say that they did huge things like that that will probably be in the history books."

A handful of U.S. military personnel will remain in the country, working with the U.S. Embassy to help with arms sales and training for Iraqi forces. Talks could resume next year on whether more U.S. troops can return for future training missions.

In the meantime, U.S. officials say there will be roughly 16,000 people involved in the American diplomatic effort in Iraq.

About 2,000 will be diplomats and federal workers. The remaining 14,000 will be contractors -- roughly half involved with security.

NBC News, msnbc.com staff, Reuters and The Associated Press contributed to this report.

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