WASHINGTON — The assassination of former Pakistani Prime Minister Benazir Bhutto has dealt a severe blow to U.S. efforts to restore stability and democracy in a turbulent, nuclear-armed Islamic nation that has been a critical ally in the war on terror.
While not entirely dependent on Bhutto, recent Bush administration policy on Pakistan had focused heavily on promoting reconciliation between the secular opposition leader who has been dogged by corruption allegations and Pakistan's increasingly unpopular president, Pervez Musharraf, ahead of parliamentary elections set for January.
In Washington and Islamabad, U.S. diplomats urged that Jan. 8 elections should not be postponed and strongly advised against a reimposition of emergency rule that Musharraf had lifted just weeks ago.
FBI and Homeland Security officials sent a bulletin late Thursday to U.S. law enforcement agencies citing Islamist Web sites as saying al-Qaida had claimed responsibility for the attack and that the group's No. 2 leader, Ayman al-Zawahri, had planned it.
The intelligence community is using all of its resources to determine who was behind the Bhutto assassination, Director of National Intelligence spokesman Ross Feinstein said. But he added, "We're in no position right now to confirm who may have been responsible for the attack."
FBI spokesman Richard Kolko said the bureau was reviewing the al-Qaida claims for any intelligence value. "The validity of those claims are undetermined," he said.
The United States has poured billions of dollars in financial assistance into Pakistan since Sept. 11, 2001, when Musharraf made a calculated decision to align his government with Washington in going after al-Qaida and the Taliban in neighboring Afghanistan. That move is blamed for several unsuccessful assassination attempts on him.
But it was not immediately clear, however, what if any influence Washington might have or whether Bhutto's death would drive the United States into a deeper embrace of Musharraf, whom some believe offers the best chance for Pakistani stability despite his democratic shortcomings.
"This latest tragedy is likely to reinforce beliefs that Pakistan is a dangerous, messy place and potentially very unstable and fragile and that they need to cling to Musharraf even more than they did in the past," said Daniel Markey, who left the State Department this year and is now a senior fellow at the private Council on Foreign Relations.
"The weight of the administration is still convinced that Musharraf is a helpful rather than a harmful figure," he said.
Amid the political chaos and uncertainty roiling the country in the wake of Bhutto's slaying, U.S. officials scrambled Thursday to understand the implications for the massive aid and counterterrorism programs that have been criticized by lawmakers, especially as al-Qaida and Taliban extremists appear resurgent along the Pakistan-Afghan border.
Underscoring the concerns, a grim President Bush interrupted his vacation to personally condemn Bhutto's murder, demanding that those responsible be brought to justice and calling on Pakistanis to continue to press for democracy.
"We urge them to honor Benazir Bhutto's memory by continuing with the democratic process for which she so bravely gave her life," Bush told reporters at his Texas ranch, before speaking briefly to Musharraf by phone.
Secretary of State Condoleezza Rice said Bhutto's assassination would "no doubt test the will and patience of the people of Pakistan" but called on the Pakistani people in a statement "to work together to build a more moderate, peaceful, and democratic future."
Yet such calls could fall on deaf ears, experts said.
"The United States does not have a great deal of leverage where Pakistan is concerned," said Wendy Sherman, who served as counselor to former Secretary of State Madeleine Albright. "And at the end of the day, the decisions are going to be made by the Pakistani people and by the leadership of Pakistan and not by the United States."
Other analysts warned that Bhutto's assassination might further damage Musharraf, whose democratic credentials have been seriously tarnished by growing authoritarianism, and have lead to widespread unrest.
"Legitimacy for Musharraf will be deferred if not impossible," said Christine Fair, a South Asia expert at the RAND Corporation. "The U.S. likely does not have a plan for this contingency as Musharraf remains a critical ally and because Bhutto's participation was hoped to confer legitimacy to the upcoming January elections."
She also warned that the murder could embolden militants in Pakistan to seek out other high-profile targets.
Bhutto, who served twice as Pakistan's prime minister between 1988 and 1996, was mortally wounded Thursday in a suicide attack that also killed at least 20 others at a campaign rally in Rawalpindi. She had returned to Pakistan from an eight-year exile on Oct. 18 when her homecoming parade in Karachi was also targeted by a suicide attacker.
The attempt on her life added to U.S. concerns about the country that had already been heightened by the situation in Pakistan, largely ungoverned frontier provinces where a truce between Musharraf's government and tribal leaders is credited with helping extremists regroup and reorganize.
In addition, Musharraf's declaration of emergency this fall, along with a clampdown on opposition figures and judges, irritated the administration, which was criticized in Congress for lax oversight of the nearly $10 billion in U.S. that poured into the country since he became an indispensable counterterrorism ally after 9/11/.
Under heavy U.S. pressure, Musharraf resigned as army chief and earlier this month lifted emergency rule to prepare for the elections. Bhutto's return and ability to run for parliament had been a cornerstone of Bush's policy in Pakistan.
Congress last week imposed new restrictions on U.S. assistance to Pakistan, including tying $50 million in military aid to State Department assurances that the country is making "concerted efforts" to prevent terrorists from operating inside its borders.
Under the law, which provides a total of $300 million in aid to Pakistan and was signed by Bush on Wednesday, Secretary of State Condoleezza Rice also must guarantee that Pakistan is implementing democratic reforms, including releasing political prisoners and restoring an independent judiciary. The law also prevents any of the funds from being used for cash transfer assistance to Pakistan, but that stipulation had already been adopted by the administration.
EDITOR'S NOTE _ Matthew Lee covers foreign affairs and diplomacy for The Associated Press.
Associated Press reporters Charles Babington, Desmond Butler, Eileen Sullivan and Matt Apuzzo in Washington and Ben Feller in Crawford, Texas, contributed to this report.