STORY HIGHLIGHTS
- Tehrik-i-Taliban Pakistan are not the Afghan Taliban
- Its goal is to bring down the Pakistani government
- The TTP first took the global spotlight with the attempted Times Square bombing in 2010
(CNN) -- While its recent attack on a military school in Peshawar, Pakistan brought international outrage, the Pakistani Taliban has long taken credit for an extensive list of assaults on civilians and the military in the country's largely-ungoverned tribal areas along the Afghan border -- and further afield.
The banned Islamist group, which has intimate links to the Afghan Taliban and al Qaeda, unabashedly confirmed it was responsible for the deadly attack on the army-run school, as well as the attempt to kill teen activist Malala Yousufzai in 2012.
But before that, the group, formally known as Tehrik-i-Taliban Pakistan (TTP), took the global spotlight when Faisal Shahzad, a Pakistani-American, attempted to detonate a car bomb in New York's Times Square in May 2010. The TTP took responsibility, and Shahzad testified that he had received training from them.
The following September, the U.S. State Department designated the TTP a "Foreign Terrorist Organization."
Are they "the Taliban?"
They are not "the Taliban" that the U.S. forces have been at war with in Afghanistan, according to Raza Rumi, director of policy and programs at the Jinnah Institute, a Pakistani think tank. But that they adopted the name "Taliban" is no coincidence.
The group is very closely linked with its namesake in Afghanistan as well as with al Qaeda. It shares its religious extremist ideology -- but is its own distinct group.
The TTP also has a different goal, but its tactics are the same, says the analyst.
"Their primary target is the Pakistani state and its military," he says. "It resents the fact that it (Pakistan) has an alliance with the West, and it wants Sharia to be imposed in Pakistan."
Another terrorism analyst notes that "there is a shared heritage between the two groups."
"The Pakistani Taliban emerged as a power alongside the Taliban as a kind of network of support," says Matthew Henman of IHS Jane's Terrorism and Insurgency Centre.
During the Soviet occupation of Afghanistan, fighters from Pakistan crossed over the border to fight. They retained close relations with the Taliban after returning home, Rumi says.
There are other militant groups in Pakistan's tribal region not under the umbrella of the TTP, who support the Taliban but do not pursue Tehrik-i-Taliban's goals of replacing the Pakistani state with an Islamist one.
READ MORE: Taliban school attack: What do the militants want?
Where do the TTP's roots lie?
Pakistan's army began hunting various militant groups in the semi-autonomous regions along Pakistan's border with Afghanistan, known as the Federally Administered Tribal Areas (FATA), in 2002.
In reaction, militant "supporters of the Afghan Taliban in the tribal areas transitioned into a mainstream Taliban force of their own," according to the Council on Foreign Relations.
In 2007, like-minded militias in Pakistan's tribal region came together under the command of Baitullah Mehsud, who was killed in a U.S. drone strike in 2009.
As a result of its beginnings, Tehrik-i-Taliban are not a unified fighting force but a coordinated coalition of militias.
"Since its formation, the TTP have been dominated by one tribe," Henman says. "That is the Mehsud tribe." When Baitullah Mehsud died, factions competed for Tehrik-i-Taliban's leadership.
Who is their current leader?
Baitullah's successor, Hakimullah Mehsud, was killed in a U.S. drone strike in November 2013, setting off a power struggle among top commanders of the TTP that led to violent clashes in which dozens of people were killed.
Appointed by a tribal council, Mullah Fazlullah has stood at the helm of the TPP since Mehsud's death. He hails from the country's Swat valley and is the first TTP leader who is not a Mehsud. He has struggled to contain internal discord among the group's factions, especially those within the Mehsud tribe, which makes up the majority of the TTP.
The militant groups control different regions within the tribal areas and often have different agendas and political objectives. The factions don't always speak with one voice, although it is widely believed they now recognize Mullah Fazlullah as their leader.
The TTP may have started in the tribal regions, but have since expanded their network.
They are "not just guys hiding in mountains or caves," Rumi explains. They maintain loose factions spread out as far as Punjab province.
"They have also been joined by criminal gangs" to raise money through kidnappings and extortion. But the TTP have maintained the coalition nature of their roots, which leads to internal strife.
The TTP's opposition to the government and its allies, particularly the United States, has galvanized them beyond their differences.
"When (former president Gen. Pervez) Musharraf sided with the U.S. in 2001 after the 'you are either with us or against us' line from (then-President George W.) Bush, this is when the Taliban began to resent the military," Rumi says.
The TTP do not encompass all militant groups in the tribal regions but does work together with some, such as the Haqqani Network.
What is the Pakistani Taliban's mission?
The TTP are fighting to overthrow Pakistan's government via a terrorist campaign, according to the U.S. State Department.
"They reject the Pakistani constitution," says Rumi. "They reject the democratic process in Pakistan."
Because of Pakistan's alliances with the United States and other countries, the Pakistani Taliban also attack foreign interests in and outside of Pakistan.
Within Pakistan, Tehrik-i-Taliban often target members of Pakistan's armed forces but also kill civilians for political and religious reasons. In a December 2009 bombing of a mosque frequented by Pakistani military personnel, the group killed 36 and wounded 75.
In March 2011, a TTP bomb planted at a natural gas station killed dozens.
An attack on a Sufi shrine in April 2011 killed more that 50 in Dera Ghazi Khan, said the U.S. State Department, which also suspects the group may have been involved in the killing of former Pakistani Prime Minister Benazir Bhutto in 2007.
Assaults on U.S. and other foreign interests have included attacks on a military base in Afghanistan and a U.S. Consulate in Peshawar. The TTP have also claimed responsibility for the assassination of a Saudi Arabian diplomat.
"Their ambitions are linked to the agenda of al Qaeda," says Rumi. They would like to bring down the West and the United States, but "given their capacity and network, they are overreaching."
Pakistan horror: When the war comes to schools
Who have they targeted?
The latest outrage, at the Peshawar military school, saw TTP attackers recently gunning down students taking an exam. It was one of the deadliest incidents inside Pakistan, according to the University of Maryland's Global Terrorism Database.
They said they were taking revenge for the killing of hundreds of innocent tribesmen and their children during a recent offensive by the Pakistani military.
One of their most notable targets is Nobel laureate Malala Yousafzai, whose blog entry exposing how TTP target schools in her region coincided with a decree in early 2009 forbidding girls from attending school.
She was singled out and shot on October 9, 2012 as she rode to school in a van with other girls. When she survived her injuries, a TTP spokesman promised they'd finish the job the next time.
In May 2010, the group has attempted to bomb Times Square in New York City as an act of revenge against the United States.
Although the U.S. military does not pursue the Pakistani Taliban within that country's borders, the CIA has hammered the TTP and other targets in the tribal regions with drone strikes, which have inflicted heavy losses but not stamped it out.
READ MORE: Attack on Pakistani schoolgirl galvanizes anti-Taliban feeling
Why is the Tehrik-i-Taliban Pakistan so difficult to fight?
The Pakistani military has been at this for a long time, Rumi points out, and although there have been successes, the fight drags on in a cat-and-mouse game.
"Tribal areas have for decades now been a no-go area for the Pakistani state," Henman says, and its security forces have not been able to establish a consistent presence there. They are left launching sporadic missions and then withdrawing.
"The militants invariably get pushed out of their strongholds," says Henman. Then they come back when the military is gone. "It's an ink blotting exercise for the Pakistani government."
"The impetus from the Taliban-type of movement is the fight against the military," Rumi says. Fighting them is what caused them to form in the first place. De-escalation should be part of the solution.
"The timely exit of the U.S. forces from Afghanistan is so important not only for Afghanistan but for Pakistan as well," Rumi says.
The London analyst agrees. "Absolutely," says Henman, getting the United States out of Afghanistan "is the key part of their religious motivation."
Like their Afghan allies, the Pakistani Taliban believe it must protect Islamic lands from "infidel invaders." "Pakistan's tacit support for the U.S. efforts in Afghanistan" exacerbates the situation in Pakistan, Henman adds.
Is Pakistani intelligence in cahoots with militants?
Western officials have accused Pakistan's Inter-Service Intelligence agency of colluding with militant groups. Discovering Osama bin Laden within the country's borders in the city of Abbottabad, where there is a dominant military presence, increased suspicions of cooperation in the West.
"There have been a number of allegations by U.S. officials," Henman says. Adm. Mike Mullen in particular accused the ISI of funding and supporting militants. "The (Pakistani) government has explicitly denied it," Henman says, and he himself has seen "no concrete evidence."
The accusations involve groups operating in Kashmir, he says, and Lashkar-i-Taiba, operating within Afghanistan, but he finds it hard to believe the ISI would support the TTP, because they target the ISI and the military.
"You can never draw any kind of definite conclusion," he says, "but it seems unlikely."
How should the government respond?
Rumi recommends a "holistic strategy, which includes military, political and institutional solutions." In the end, the people of the tribal regions need to be reintegrated into Pakistani society.
Henman agrees. "If there is a solution to be found, it is unlikely to be purely military," he says. The TTP can survive massive military efforts and keep bouncing back.
Earlier in 2014, the government held tentative peace talks with the TTP but it suspended them after two brazen attacks around Pakistan's largest airport in Karachi in June.
Since then, Pakistan's military has been conducting a ground offensive aimed at clearing out TTP and other militants in the loosely-governed tribal areas of northwestern Pakistan. The campaign has displaced tens of thousands of people.
READ MORE: Inside militants' secret tunnels in Pakistan
CNN's Laura Smith-Spark, Tim Lister and Sophia Saifi contributed to this report.