The arrest of a Pakistani-born American man for driving a failed car bomb into New York's Times Square on Saturday has once again thrust the south Asian country under the global spotlight as a center of terrorism, just as the Obama administration seeks to shore-up Pakistani support for Washington's fight in Afghanistan.
Mehsud also promised to launch terrorist attacks on major American cities. Mehsud, earlier reported to have been killed in a January attack by a U.S. drone, warned, "The time is very near when our Fedayeen (fighters prepared to sacrifice themselves) will attack the American states in their major cities."
"Our Fedayeen have penetrated the terrorist America. We will give extremely painful blows to the fanatic America," Mehsud threatened.
While Pakistani officials still disagree on whether it was genuinely Mehsud who appeared in the video or a look-alike, news of Shahzad's arrest has prompted speculation over his possible direct or indirect links to Islamic militants based in the country -- notably the Taliban.
"This arrest will prompt many people to ask once again the very obvious question, which is, how rapidly are the Taliban emerging as a threat to Pakistan and the world," Hasan Askari Rizvi, a respected Pakistani commentator on security affairs told CBS News.
Pakistani Interior Minister Rehman Malik told reporters in Islamabad the U.S. would have Pakistan's full cooperation in investigating the case.
However, other senior Pakistani government officials say the case has to be seen primarily as a domestic U.S. security issue, given that the only named suspect thus far is a U.S. national who intended to commit a crime on U.S. soil.
But Rizvi disagreed.
"You can't keep on pretending that a case of this kind will not have links to elements here (in Pakistan). We need the case to be investigated further," he told CBS News. "At the very least, the involvement of a man of Pakistani origin raises new questions over how far Islamic militants are determined to plan new attacks."
Further details of Shahzad's exact links to his native Pakistan, such as where his family are located, are yet to be revealed. Western diplomats in Pakistan suggest that, based strictly on his name, he may be from the populous Punjab province. If that is the case, the spotlight will ultimately fall on militant groups based in that province of about 100 million people.
In Lahore, the provincial capital of the Punjab, a government official told CBS News: "Faisal and Shahzad are very common names in the Punjab. If it is discovered that he travelled to Pakistan recently and spent most of his time in Punjab, that will prompt further investigations."
Suggestions of links to other regions away from the border with Afghanistan, such as the southern port city of Karachi, will also inevitably force the government to open new fronts.
Politically speaking, for Pakistan's U.S.-allied President Asif Ali Zardari, expanding an ongoing anti-Taliban military campaign in border areas into the densely packed Punjab would bring huge new risks, warned the provincial government official, who spoke to CBS News on condition of anonymity.
"We have to see how deep this guy's connections are and exactly where in Punjab," added the provincial official. "If it turns out that he was backed by a group from the Punjab, that will present the government with very difficult choices."
"Any eventual decision to begin attacking suspected bases of militants in the Punjab will probably be retaliated, so there might be more bloodshed," concluded the official.
A western diplomat in Islamabad says, "the road ahead will get rough for Pakistani authorities if they are forced to open more fronts. The New York attempt could unleash a major new phase for Pakistan's battle against militants, with consequences that will be hard to figure out at this stage."