– At his ranch in Texas, President Bush condemned Thursday's assassination of Pakistani opposition leader Benazir Bhutto as a "cowardly act" and said the perpetrators of the attack must be brought to justice.
He also called on President Pervez Musharraf to continue Pakistan's democratic process – in part, Mr. Bush said, to honor Bhutto's memory and efforts.
"When intelligence agencies make their lists of the world's most dangerous places, Pakistan is always at the top," says John Hulsman, a scholar in residence at the German Council on Foreign relations in Berlin. "Today it got a lot more dangerous."
The leverage the US has over Pakistan includes $10 billion in aid the Bush administration has given to Musharraf since 9/11.
That aid continues to flow, despite widespread criticism that little of that money has gone toward fighting Al Qaeda and other extremists.
The US has been working on developing a new counter-extremism plan in Pakistan, but its implementation in the tribal areas in particular has been troubled by slow coordination and lack of cooperation from some Pakistani security elements.
Even before Thursday's assassination, US officials were debating how much pressure to apply to Musharraf for freer campaign and election conditions.
Now Musharraf – who warned of turmoil as he faced outside pressure to set a date for elections and to lift the state of emergency he had declared in November – is likely to say "I told you so" and hunker down even more.
But that reaction, and a further isolation of Musharraf, is exactly what Al Qaeda and other Islamic extremists operating in the country will be looking for, analysts say.
Calls for US to press Musharraf
Fearing Musharraf could use the moment to re-impose the state of emergency only lifted on Dec. 15, they say the US must use the substantial leverage it wields with Musharraf to forestall an over-reaction that would play into the hands of Islamic extremists.
"This is the time when the Bush administration must really put the pressure on Musharraf not to stop the political process as he might be tempted to do," says Syed Farooq Hasnat, former chairman of the political science department at the University of the Punjab in Lahore, Pakistan, and now an adjunct scholar with the Middle East Institute in Washington. "The extremists can only be reduced in their influence and numbers by more political process and openness, not less."
Earlier this year, the US spent months negotiating a power-sharing deal between Ms. Bhutto and her bitter rival Musharraf.
Bhutto's return to Pakistan in October after years of exile would be the best way to ease the country into more representative governance while maintaining the stability that Mr. Musharraf appeared to offer in a fragile nuclear-power state with mounting Islamic extremism, the US reasoned.
But once Musharraf declared martial law in November, Bhutto pulled out of the deal and called for Musharraf to resign.
Now that Mrs. Bhutto is gone – killed Thursday in a suicide bombing at a campaign rally in anticipation of Jan. 8 parliamentary elections – the already dicey prospects for Pakistan's stability have turned all the more grim.
For the US, the options on the horizon are not bright.
"The whole idea behind the US plan was to bring [Bhutto] and Musharraf together, thereby wedding the hard power of the Army and an increasingly isolated leader to a populist democratic movement," Mr. Hulsman says. "The reasoning was that this broadening of support [for Musharraf] would stabilize the most volatile nuclear power in the world – but now that plan goes out the window."
Without Bhutto – the more pro-Western and pro-American of the major candidates for prime minister – attention turns to the other top candidate, former prime minister Nawaz Sharif, whose Pakistan Muslim League (N) is much less favorable to American influence and interests in the country.