Has US Lost Influence over the Crisis in Pakistan?

Pakistan has long presented a vexing policy conundrum for the US. Its nuclear-weapons lab leaked technology to Iran and North Korea and al Qaeda's leaders have taken refuge in its tribal lands. Washington played down those problems as long as it had a stable alliance with Islamabad. But since President Pervez Musharraf declared emergency rule two weeks ago, the US has struggled to stabilize this key ally in the war on terror, urging a return to civilian rule while risking instability that could aid terrorists. Musharraf has remained defiant in his grip on power despite a visit by Deputy Secretary of State John Negroponte, who also met with opposition politicians, in a search for political alternatives. With whom did he speak and, at this point, can the US really help them? Can the US cut aid without pushing Pakistan to the brink of chaos?