A recent US-led ground assault across the border on a Pakistani tribal region, said to have killed at least 15 people, prompted protests from the government and suggested that American patience with Islamabad is wearing thin.

Pakistani President elect Asif Ali Zardari, widower of former Pakistani prime minister Benazir Bhutto, stands with his daughters as he speaks with parliamentarians and supporters of his ruling political party PPP at a celebration reception dinner in Islamabad September 6, 2008. [Agencies]

Like his late wife, Zardari is generally considered a pro-West liberal. He is not expected to change Musharraf's commitment to the US war on terrorism, insisting the battle against militants is Pakistan's own war. But a key test will be how much clout Zardari wields over the powerful military.

As president, Zardari will have the power to dissolve Parliament and appoint army chiefs, and chairs the joint civilian-military committee that controls Pakistan's nuclear weapons.

He has said he will relinquish some of the power accumulated by Musharraf. However, Zardari has not made clear how far he will go, sustaining concern that one would-be strongman is replacing another.

Friends say Zardari remains underestimated, even after he nimbly stepped into Bhutto's political shoes and outmaneuvered both Sharif and Musharraf.

"I've seen a changed person after his wife's death. I've found him to be an extremely astute politician, which was perhaps overshadowed by the towering personality of his wife," said Wajid Hasan, Pakistan's High Commissioner in London.

Many ordinary Pakistanis also remain to be convinced.

"We want him to make parliament sovereign and to evolve a clear policy on the war on terror" as well as tackle crippling inflation, said Muhammad Azam, a 33-year-old bank employee from Lahore. "I want to convey to Zardari that he is not a leader by choice, but by chance. Now he has to prove his worth."