Of all the challenges facing President Obama, none is more difficult to solve than the basket case that is Pakistan. The Muslim nation - whose support is critical to the U.S. mission in Afghanistan - is not only broke and on tenterhooks with its arch enemy India, it is now at war with Muslim extremists inside the country who are trying to destroy the government of President Asif Ali Zardari.
As 60 Minutes correspondent Steve Kroft first reported in February, the growing insurgency run by the Taliban and al Qaeda is threatening the stability of a key U.S. ally that is believed to have as many as a hundred nuclear weapons.
How do Pakistanis feel about U.S. drones operating within their borders? CBS News' Farhan Bokhari in Islamabad.
Also, read 60 Minutes producer Draggan Mihailovich's account of traveling into Taliban territory.
For all of its 62 years, the government of Pakistan and its military have been obsessed with one thing: India, the enemy next door to the east with whom it has fought three wars. And every day for 50 of those years its soldiers at one of the border crossings have stared down their Indian counterparts, as their flags are raised and lowered.
But the biggest threat facing Pakistan today comes from within, from its lawless tribal territories on the western frontier, where the Taliban and al Qaeda were allowed to regroup and carry out attacks against U.S. troops across the border in Afghanistan, and now against the Pakistani government.
During the past year, Islamic extremists have launched more than 600 terrorist attacks inside the country, killing more than 2,000 people. One suicide bombing last September, at the Marriott Hotel in the capital of Islamabad, killed 60 people just minutes away from the presidential offices, now occupied by a very unlikely leader, Asif Ali Zardari.
Asked how important it is to stop extremism, President Zardari told Kroft, "It's important enough. I lost my wife to it. My children's mother, the most populist leader of Pakistan. It's important to stop them and make sure that it doesn't happen again and they don't take over our way of life. That's what they want to do."
Zardari's late wife was Benazir Bhutto, who was supposed to be leading the country. But the former prime minister was assassinated, most likely by the Pakistani Taliban, after returning from exile 17 months ago. Until then, Zardari had spent more time in prison on corruption charges than he had in government service.
But parliament elected him president last fall, and he has spent much of his time dealing with the Taliban insurgency that has spread across the countryside. "They do have a presence in huge amounts of land in our side. Yes, that is the fact," Zardari acknowledged.
North of the capital, in an area known as Swat, the Taliban have seized control, terrorizing villages and imposing Islamic law. Beheadings are common, signs in the market place read "no women allowed," and a few months ago the Taliban blew up five girls schools.
"Right now, you have a situation in the Swat area. It's only three hours from Islamabad where the Taliban is very strong there," Kroft remarked. "How did that happen?"
"It's been happening over time. And it's happened out of denial. Everybody was in denial that they're weak and they won't be able to take over. That, they won't be able to give us a challenge. And our forces weren't increased. And therefore we have weaknesses. And they are taking advantage of that weakness," Zardari explained.
For years, the Taliban were permitted to operate openly in the border regions of Pakistan. Their leaders even held news conferences. The government was unwilling to take them on politically or militarily. Now Pakistan is facing a monster it helped create, and has been forced to act. It's deployed 120,000 troops to clear the Taliban from their sanctuaries.
60 Minutes went with them to one of the most dangerous places in the world, the border area adjacent to Afghanistan's Kunar province, the Princeton of international terrorism, where many believe al Qaeda's top leadership is being hosted by the Taliban.
We landed in a place called Bajaur, a district in the tribal territories that sits astride a major Taliban infiltration route and the scene of the Pakistani military's biggest offensive ever against the Taliban and al Qaeda. Gen. Tariq Khan is the commander of Pakistan's forces in the tribal territories.
"We considered Bajaur to be the center of gravity, from where the militants had access to Afghanistan," Khan told Kroft.
Asked what the fighting was like there, the general said, "We had to fight compound to compound. And every inch, we had to take a hit."
Khan told Kroft he was surprised by the enemy's numbers and their intensity. "The kind of tenacity. The need to hold onto ground. There were no surrenders. As much as people willing to die."
It took the Pakistani military five months of heavy fighting to gain a fragile foothold over an area about half the size of Rhode Island. When 60 Minutes was there in January, there was still sporadic sniper fire as the frontier corps cleared out the last pockets of resistance.