The troubled U.S. relationship with Pakistan – whose tensions could doom any hope of stability in Afghanistan after 2014 – could be about to get worse after last week's elections.

I don't just mean that Nawaz Sharif, the new prime minister-designate, has taken a tough public stance against continued U.S. drone strikes on militants in Pakistan's tribal areas. Going way beyond that, Sharif is likely to take a much more conciliatory approach towards Islamic militants - both domestic and Afghan (in which he will be abetted by other smaller parties, including that of cricket-star-turned politician, Imran Khan.

So says Husain Haqqani, a former Pakistani ambassador to the United States.

Haqqani doubts that the two-time former premier will arrest leaders of domestic terrorist groups who have carried out terror attacks in India, or who are regularly murdering minority Shiite Muslims within their own country.

Sharif says he will pursue negotiations with Pakistan's Taliban groups, despite the repeated failure of past such talks. Haqqani, who believes the local Taliban present a direct threat to the Pakistani state, calls this "some kind of appeasement.".

Sharif is also likely to keep providing safe havens for Afghan Taliban groups, given his support for the Afghan Taliban during a previous term as prime minister in the late 1990s. At that time, Sharif's government was one of only three that recognized the Taliban government in Afghanistan (along with Saudi Arabia and the United Arab Emirates.)

Haqqani does not believe that flailing U.S. efforts to promote talks with the Taliban – which would require Pakistan's close cooperation – will have any greater success under the Sharif government.

When I interviewed Sharif in December 2007, shortly after he had returned from years of forced exile in Saudi Arabia, he was very opposed to Pakistani military efforts to curb Taliban groups even though they had been attacking civilians and government institutions. Sharif endorsed the popular narrative that the army's battle with local militants is a war forced on Pakistan by the United States.

In that interview, Sharif made clear that he would like to release Dr. A.Q. Khan, the father of Pakistan's nuclear bomb, from house arrest. Khan is one of the world's most notorious nuclear proliferators, having shared or sold critical nuclear secrets to North Korea and Iran.

Bottom line: Pakistan under Nawaz Sharif is not going to make it any easier for the United States to withdraw from Afghanistan and leave behind a stable country that is not a renewed haven for terrorists. Nor will he recognize the threat that Pakistan's own Taliban present to its people and the future of the state.