PHILADELPHIA -- The scenes were grisly.
The U.S.-educated Benazir Bhutto, first female prime minister of Pakistan, newly returned from years in exile, was riding in a caravan through Karachi streets surrounded by tens of thousands of adoring supporters. Then came the explosions. Fire and body parts, most likely the work of al-Qaida, perhaps with aid from Taliban allies.
Ms. Bhutto survived; more than 130 died. But the blasts were a wake-up call for her, Pakistan's President Pervez Musharraf, and us.
While Americans are focused on the Iraq war and a possible Iran war, the greatest danger to us lies within Pakistan. So says the U.S. government's latest National Intelligence Estimate on "The Terrorist Threat to the U.S. Homeland." It concludes that "the most serious terrorist threat to the homeland is and will remain" al-Qaida, which has established a haven in the tribal areas of Pakistan.
America's ally, General Musharraf, has failed to prevent al-Qaida and the Afghan Taliban from establishing a base in mountainous regions along the border with Afghanistan. His army has proved ineffective at fighting insurgents.
Ms. Bhutto charges that Pakistan's intelligence agencies are still penetrated by an old guard that helped train Afghan militants to fight the Soviet Union in the 1980s - and is still sympathetic to jihadis. This old guard is also said to be helping homegrown Islamic radicals who are fighting India over Kashmir.
On Friday, Ms. Bhutto accused "people in positions of power" of providing logistical support for extremists who tried to kill her. Of course, Pakistan's government denies this. But the facts show Mr. Musharraf has been unwilling or unable to crush extremists at home who have tried to kill him, too.
The attempted murder of Ms. Bhutto reflects the growing ability of Pakistani militants to destabilize a country that (unlike Iran) already has nuclear weapons. Pakistan is also a nation whose leading nuclear scientist, Abdul Qadeer Khan, was able for years to sell nuclear technology to countries such as Libya, Iran and North Korea - supposedly without his government's knowledge. The West's nightmare scenario would be the illicit transfer of Pakistani technology to al-Qaida or other fanatic Islamists.
Yet, for all its horror, the Karachi outrage could finally generate the necessary momentum to confront this threat.
