On Sunday, U.S. Attorney General Eric Holder officially dropped the theory that alleged Times Square bomber Faisal Shahzad was a "lone wolf" — a theory Gen. David Petraeus had espoused just days before. Holder and other U.S. officials now say Shahzad was working with, and on behalf of, the Pakistani Taliban (also known as Tehrik-e-Taliban Pakistan or TTP). (Watch an AP report about Shahzad's Pakistani ties.) Here's what we know about Shahzad's accomplices, and what Pakistan's involvement could mean for America's security:
What exactly did Holder say?
"We've now developed evidence that shows that the Pakistani Taliban was behind the attack," Holder told ABC's This Week. "We know that they helped facilitate it. We know that they probably helped finance it. And that [Shahzad] was working at their direction." White House counter-terrorism adviser John Brennan elaborated, calling the Terhik-e-Taliban "almost indistinguishable" from al Qaeda.
So the "lone wolf" theory is dead?
Apparently, although that was the original assessment of officials ranging from General Petraeus to Homeland Security Secretary Janet Napolitano. By contrast, Pakistan's military had played down the possibility of a Pakistan connection.
What's changed in two days?
Officials aren't being specific. Shahzad has continued talking to investigators, and Brennen said Pakistani officials have been "very cooperative." The FBI is also getting information from the Pakistani-American community.
What are the implications of TPP's involvement?
If Holder and Brennan are right, this would be the first attack by the Pakistani Taliban on U.S. soil, and proof that it is further broadening its reach beyond Pakistan's borders.
How dangerous is the Pakistan Taliban?
As a training ground, very, says Fareed Zakaria in The Washington Post, noting that the British government says it can trace 70 percent of the terror plots it has uncovered in the last decade to Pakistan. Even as radical Islamic groups in other countries are losing political support, Zakaria says, "dozens" of jihadist organizations continue to flourish in Pakistan (under the TTP's umbrella), due to a history of government leniency.
Who did Shahzad allegedly take orders from?
U.S. officials point to Hakimullah Mehsud, 30, a ruthless wanted man who leads the TTP and initially claimed responsibility for the failed attack. Pakistan's government has a $600,000 bounty on Mehsud's head, and several U.S. Predator drone attacks have targeted him. (Reportedly, Shahzad has also described himself as a follower of Anwar al-Awlaki, the extremist cleric who's also been linked to the Fort Hood killer. See "Who is Anwar al-Awlaki?").
What motivated the Times Square attack?
Shahzad has reportedly tied his attempted bombing to the U.S. drone attacks in North Waziristan, a TTP stronghold where he says he trained. No more specific information is available yet.
What does the U.S. plan to do now?
Top U.S. officials are pressuring Pakistan to clean up North Waziristan, as it has with other Taliban-controlled areas. "You can't pretend any longer that this is not going on," U.S. Gen. Stanley McChyrstal reportedly told Pakistani militar chief Gen. Ashfaq Parvez Kayani. "We are saying, 'Sorry, if there is a successful attack, we will have to act'" inside Pakistan, an unidentified U.S. official adds. Hillary Clinton has also warned of "very severe consequences."