Taliban insurgents recently vowed to carry out new "infiltration" attacks aimed at killing and demoralizing U.S., allied, and Afghan military forces as part of the spring military offensive, according to U.S. officials.
The expected increase in what the Pentagon calls "insider" attacks by Taliban sympathizers or infiltrators followed an April 27 statement by the Islamist terror group.
It was the first time the Taliban identified insider attacks as a key tactic.
U.S. military officials have said the Taliban shifted to insider attacks as U.S. and allied forces became more adept at countering improvised explosive devices—deadly roadside bombs that have killed and injured hundreds during the 12-year war.
Pentagon spokesman Cmdr. Bill Speaks said the military is aware of the threat.
"As we approach the traditional fighting season, the frequency of insider attacks is likely to increase," Speaks said. "But we will not allow this insidious tactic to erode our will to complete the mission or hinder our partnership with the [Afghan National Security Forces] in defeating those who threaten Afghanistan's future."
Sixty-two coalition troops were killed in 46 attacks in 2012, Speaks said, noting that from 2007 to 2011, 42 insider attacks resulted in 69 coalition deaths. A total of 34 Americans were killed by the method last year.
"So far for 2013, there have been four attacks and four coalition deaths," he said.
The most recent incident occurred May 4 when two U.S. Marine Corps special operations group commandos were killed by an Afghan National Army soldier who fired on them.
The Taliban statement announcing the spring offensive was posted on the group’s official Voice of Jihad website under the name of the "Islamic Emirate's Leadership Council." The council is headed by Taliban leader Mullah Omar.
The statement signaled the beginning of the fighting season in Afghanistan. Insurgent attacks generally decline during the fall and winter months and take off in the spring and summer.
The Taliban are calling their latest offensive the "Khalid bin Walid" offensive and called planned insider attacks as a "qualitatively unique military tactic" targeting foreign "invaders." Khalid bin Walid was a companion of Muslim founder Muhammad.
In addition to insider attacks, the Taliban also are planning "collective martyrdom attacks," presumably a reference to car bombs and other bombing attacks. Announced targets include military bases, diplomatic centers, and air bases.
However, the reference to insider attacks has raised concerns at the Pentagon, officials said.
The Taliban statement said there would be the "systematic and coordinated" use of "infiltrating attacks."
The infiltration operations will be targeted on gaining access "inside the enemy's centers."
Insider attacks are carried out by Afghan security and military personnel who are influenced by the Taliban, or who are double agents dispatched or converted while in the Afghan security forces. The terrorists pose as members of the Afghan National Security Forces or Afghan police and then carry out shootings against coalition forces or Afghans working for the central government.
The goal of the spring offensive is to gain "liberation of the remaining regions of the country" from domination by "infidels" and the establishment of a government based on Islamist Sharia law, the statement said.
Last year’s statement on the spring offensive did not mention insider attacks or collective martyrdom operations. It said the group would seek to expand Taliban influence rather than reaching a concluding victory.
"The threat of insider attacks is very real and creates deep distrust at time when training the Afghan forces is critical to the way ahead," said Rep. Duncan Hunter (R., Calif.), a member of the House Armed Services Committee.
"These attacks add an extra dimension to the security mission that existed previously, but maintaining the right security procedures and precautions are absolutely critical," Hunter said. "At this stage of the Afghan mission, it’s important that we stay on offense."
Hunter stated that the growth of insider attacks is "alarming" in a letter last August to Committee Chairman Howard P. "Buck" McKeon (R., Calif.) calling for hearings on the threat.
Then-U.S. commander in Afghanistan Gen. John R. Allen said the use of the terrorist tactic had made him "mad as hell" in September.
"We're going to get after this," Allen told CBS "60 Minutes." "It reverberates everywhere across the United States. We're willing to sacrifice a lot for this campaign, but we're not willing to be murdered for it."
A conference was held in January on the insider threat at Grafenwoehr, Germany where the International Security Assistance Force (ISAF) Insider Threat Mitigation Working Group met.
Australian Brig. Adam Findlay, chief of the Working Group, told reporters that the Taliban’s use of insider killings has two objectives: "Drive a wedge amongst the coalition countries for political pressure back home, and to try to drive a wedge between us and the Afghan forces."
U.S. Marine Corps Col. John Walsh, deputy commander of the Insider Threat Mitigation Working Group said the insider attack "is emerging as a signature weapon of this conflict."
According to Speaks, the Pentagon spokesman, some of the insider attacks were linked to personal grievances by Afghans or were the result of cultural "misunderstandings."
"The insurgency, with its continuing decline and inability to dissuade the Afghan population from the course of a secure and peaceful Afghanistan, is seeking to exploit the effects of these attacks, and those contributing factors that cause others to commit these attacks, to claim success falsely," he said.
Speaks said more Afghans were killed in insider attacks than U.S. and allied forces.
Afghanistan’s Defense Ministry issued a statement April 29 stating that its forces are prepared for the spring offensive and dismissed the Taliban threats as "propaganda."
Michael Rubin, American Enterprise Institute expert on the Afghan conflict, said insider attacks have limited military utility but can be demoralizing.
"Afghans have never lost a war, they just defect to the winning side," Rubin said in an email. "Momentum means everything. The insider attacks might only kill a handful of soldiers, but they demoralize on a far larger scale. And so, while the attack itself might only splinter the wood, the incumbent demoralization will throw the door wide open."
Infiltration attacks also can upset U.S. counterinsurgency strategy.
"It’s hard to build rapport and trust with our partners if we’re looking over our shoulder every ten seconds," Rubin said.
However, Rubin said the Taliban might hit a dead end with the strategy emphasizing insider strikes.
"It’s one thing to argue jihadists have to kill themselves to defeat the Americans, but with the Taliban spinning the transition in Afghanistan as a sign of American defeat, ultimately some Afghans will begin to ask themselves why they should be the last suicide bomber," he said.
Lisa Curtis, senior research fellow at the Heritage Foundation, said insider attacks declined significantly so far in 2013.
"As part of their summer offensive, the Taliban have pledged to reverse this trend by infiltrating the Afghan security forces," she said. "The Taliban assess insider attacks are the best way to demoralize the U.S. and NATO forces and speed up the pace of their withdrawal."
Curtis said after the U.S. military cut back joint patrols with Afghan forces last year after the increase in insider attacks, "the Taliban were elated and called the move the start of the coalition’s overall defeat in Afghanistan."
The U.S. and Afghan militaries have taken steps to curb the attacks through more careful vetting and monitoring of recruits, she said.
"The Afghan Army leadership has taken the issue of insider attacks very seriously and it is not clear that the Taliban will be able to follow through on their pledge to step up these kinds of attacks in 2013," Curtis said.