The dismissal of Gen. Stanley A. McChrystal will almost certainly embolden the Pakistanis in their plan as they detect increasing American uncertainty, Pakistani officials said. The Pakistani Army chief, Gen. Ashfaq Parvez Kayani, preferred General McChrystal to his successor, Gen. David H. Petraeus, whom he considers more of a politician than a military strategist, said people who had spoken recently with General Kayani.

Pakistan is presenting itself as the new viable partner for Afghanistan to President Hamid Karzai, who has soured on the Americans. Pakistani officials say they can deliver the network of Sirajuddin Haqqani, an ally of Al Qaeda who runs a major part of the insurgency in Afghanistan, into a power-sharing arrangement.

In addition, Afghan officials say, the Pakistanis are pushing various other proxies, with General Kayani personally offering to broker a deal with the Taliban leadership.

Washington has watched with some nervousness as General Kayani and Pakistan’s spy chief, Lt. Gen. Ahmad Shuja Pasha, shuttle between Islamabad and Kabul, telling Mr. Karzai that they agree with his assessment that the United States cannot win in Afghanistan, and that a postwar Afghanistan should incorporate the Haqqani network, a longtime Pakistani asset. In a sign of the shift in momentum, the two Pakistani officials were next scheduled to visit Kabul on Monday, according to Afghan TV.