More than a dozen officials in Washington and Islamabad from a number of countries spoke on condition of anonymity because of the fragility of Pakistan’s current political situation. The doubts that American officials voiced about whether General Musharraf could survive were more pointed than any public statements by the administration, and signaled declining American patience in advance of Mr. Negroponte’s trip.

Officials involved in the discussions in Washington said the Bush administration remained wary of the perception that the United States was cutting back-room deals to install the next leader of Pakistan. “They don’t want to encourage another military coup, but they are also beginning to understand that Musharraf has become part of the problem,” said one former official with knowledge of the debates inside the Bush administration.

That shift in perception is significant because for six years General Musharraf has sought to portray himself, for his own purposes, as the West’s best alternative to a possible takeover in Pakistan by radical Islamists.

While remote areas in northwestern Pakistan remain a haven for Al Qaeda and other Islamic militants, senior officials at the White House, the State Department and the Pentagon now say they recognize that the Pakistani Army remains a powerful force for stability in Pakistan, and that there is little prospect of an Islamic takeover if General Musharraf should fall.

If General Musharraf is forced from power, they say, it would most likely be in a gentle push by fellow officers, who would try to install a civilian president and push for parliamentary elections to produce the next prime minister, perhaps even Ms. Bhutto, despite past strains between her and the military.