Washington (CNN) -- Rank-and-file Taliban fighters in Afghanistan are tired and weakening, with some making offers to drop out of the conflict, the top U.S. commander there said.
In a rare in-depth interview with CNN's Christiane Amanpour on Wednesday, Gen. Stanley McChrystal said Taliban leaders who operate from safe havens remain confident and optimistic. But recent operations by U.S. and allied troops have pushed back the Taliban "in a number of areas" and caused "a tremendous amount of angst" in the Islamic militia's ranks, he said.
"Their fighters are tired. We see a number that have already made extensive overtures to reintegrate back into the government," McChrystal said. "So I think we've got an insurgency that is sitting safely in what they consider are safe havens. They are trying to exhort their forces who are closer to the fight, but the forces are having a tremendous problem right now and tremendous weakening."
But he said he is is particularly concerned about the security and stability of Pakistan, which is fighting its own campaign against the Taliban and has nuclear weapons.
"I think Afghanistan is critical to stability and the future of security of Pakistan, and I think the government of Pakistan understands that as well," McChrystal said.
U.S. President Barack Obama announced last week that he will be sending another 30,000 U.S. troops into the 8-year-old Afghan war, which was launched in response to the September 11, 2001, attacks on New York and Washington. McChrystal spoke with Amanpour a day after testifying to Congress about Obama's new plan for the war, which also sets a July 2011 date for the beginning of a U.S. withdrawal.
The deployment would bring the number of U.S. troops in Afghanistan to nearly 100,000. At least 25 other NATO countries are offering to contribute another 7,000 troops as well, joining about 42,000 NATO-led troops now in the country.
McChrystal, who commands both U.S. and NATO forces, said the Taliban insurgency could still destabilize Afghanistan "to the point that it would be a real risk to the region" and allow the return of al Qaeda, the terrorist network behind the 9/11 attacks.
Amanpour asked McChrystal why everyone was so queasy about the term "defeat" in Afghanistan.
"It is interesting, because in military definition, 'defeat' does not mean eradicate or wipe out an enemy," he said. "It means prevent them from being able to accomplish their mission. That, in fact, is what we are trying to do with the Taliban. To the degree to which we can degrade their capability, prevent them from access to the population, and increase Afghanistan's ability to protect its own sovereignty, we have defeated the Taliban from being an existential threat to Afghanistan."
McChrystal emphasized the importance of working with the Afghan government to help protect the Afghan people and provide time and space for better security and improved governance.
"As we provide security, there must be nation-building that occurs. But it occurs under Afghan leadership with international assistance. It cannot be a product delivered; it must be a process enabled for the Afghans," he said. "They are going to need a lot of assistance and partnership from the international community. And I think we need to offer that to them, but we also need to remember that the responsibility ultimately lies with Afghans."
McChrystal also explained the counterinsurgency strategy he's using in Afghanistan, a strategy that some have likened to spreading ink blots on paper.
"We will work with Afghan partners to establish security zones, and gradually those security zones will grow in size", he said. "And that as they connect to each other, they provide the ability for an Afghan farmer, for example, to raise crops in the central Helmand River valley and then to move with full security up to the markets of his choice. It might be Lashkar Gah. It might be Kandahar."
But McChrystal said he was cautious about drawing parallels between the conflict in Afghanistan and the Vietnam War.
"I believe that looking at lessons on experiences like Vietnam is critical," he said. "I don't think you should take counsel of your fears on everything you see, because every situation is unique."