A former CIA analyst, who helped President Barack Obama formulate his Pakistan-Afghanistan policy, sees "a very serious possibility that the next mass casualty terrorist attack on the United States will be postmarked 'Pakistan.'"
"What we're seeing going on in Pakistan now is a very dangerous phenomenon," says Bruce Riedel, Senior Fellow, Brookings Institution, in an interview with the Council on Foreign Relations, a Washington think tank.
"The ideology of Al-Qaeda, the ideology of global Islamic jihad that all jihadists should focus on the United States as the ultimate enemy, is gaining ground with groups beyond Al-Qaeda," said Riedel, who chaired a special interagency committee last year to develop Obama's Af-Pak policy.
Obama and previous Bush administrations have been pressuring Pakistan for years to shut down completely the jihadist Frankenstein that was created over three decades in Pakistan, Riedel said. But "no Pakistani government has yet been willing to take on the entire network of terrorist groups."
US Secretary of State Hillary Clinton has also raised questions about some in the Pakistani government still retaining links to Al-Qaeda, the Afghan Taliban, the Pakistani Taliban, Lashkar-e-Taiba and a host of other groups.
"We saw this in 2008 in Mumbai, when Lashkar-e-Taiba attacked Mumbai and attacked American and Israeli targets," Riedel said noting "Those are the targets of Al-Qaeda and the global Islamic jihad."
"We've now seen the Pakistani Taliban try to launch an attack on the United States of America for the first time," he said referring to the arrest of Pakistani-American Faisal Shahzad in connection to the failed car bombing in New York's Times Square.
"This spreading of the idea of global Islamic jihad is very dangerous and as it gets deeper and deeper into the extremist groups in Pakistan it means we can expect more attacks like the one we saw at Times Square, and we can expect them to become increasingly sophisticated and more capable," Riedel said.
Clinton has warned of "severe consequences" for Pakistan in the event of a successful Pakistan-based terrorist attack in the United States.
But US options to act against Pakistan are "severely limited," Riedel said arguing the best option is "to get Pakistan to do more now" in its fight against extremism, he says, by providing more weapons and technological aid.