Popular Former Prime Minister Is Back in Pakistani Politics

ISLAMABAD, Pakistan, May 26 -- Pakistan's Supreme Court ruled Tuesday that former prime minister Nawaz Sharif, the nation's most popular politician, can participate in elections despite an earlier ban.

The ruling is likely to ease political tensions in the short term but could ultimately pose a challenge for President Asif Ali Zardari, who is Sharif's main rival and whose popularity has plummeted. Although elections are not due until 2013, Sharif is now in position to reclaim the office he held twice in the 1990s.

"This is a decision welcomed by the entire nation," Sharif told reporters in the eastern city of Lahore, his base. "Today an independent judiciary is giving independent decisions."

Sharif and his brother Shahbaz had been banned from electoral politics because of previous criminal convictions that they say were politically motivated.

The brothers' reinstatement had been widely expected. This year, Nawaz Sharif led a successful movement to restore the chief justice of the Supreme Court, whom then-President Pervez Musharraf fired in late 2007.

In a statement Tuesday, Zardari congratulated Sharif and welcomed him back to electoral politics. But Sharif's branch of the Pakistan Muslim League represents the main opposition to Zardari's Pakistan People's Party, and the enmity between the men is well known.

For now, though, Sharif is supporting Zardari on several issues, most crucially the military's operation in the Swat Valley, which continued Tuesday.

Since early May, the army has been battling to oust Taliban militants who had taken control of the northwestern region. About 2.3 million people have fled since fighting began, according to provincial government statistics, but about 200,000 civilians remain trapped.

Human Rights Watch warned Tuesday that unless the government relaxes a curfew and allows food, water and medicine into the valley, there will be a "humanitarian catastrophe."

But Maj. Gen. Athar Abbas, a military spokesman, said it would not be possible to pause the offensive. "Lifting the curfew would mean letting the operational situation slip out of hand," he said. Instead, the government said it was planning to air-drop supplies to trapped residents.

Abbas insisted that the government has the Taliban fighters on the defensive, although that was impossible to verify because access to Swat is severely limited. "They're in disarray and finding ways to sneak out," he said.

Meanwhile, the army attacked Taliban positions in another of the group's northwestern strongholds, the tribal region of South Waziristan, which is home to top Taliban leader Baitullah Mehsud. Several insurgents were killed, according to local residents, and the attack fueled speculation that the army is preparing to enter that area, as well. Zardari said recently that South Waziristan would be next on the army's agenda after Swat.

The military launched the operation in Swat after the Taliban moved into the adjacent districts of Buner and Dir, in violation of a peace deal with the government. The United States has leaned heavily on the Pakistani government to take a tougher line in combating militancy.

Gen. David H. Petraeus, leader of U.S. Central Command, arrived in Islamabad on Tuesday and spoke approvingly in an interview with Radio Free Europe/Radio Liberty of the Pakistani military's willingness to "very aggressively prosecute the campaign."

"It bodes much better for Pakistan," he said.

The army said Tuesday evening that its troops had killed 29 militants in the previous 24 hours, mostly in Mingora, Swat's main city, and that six soldiers had died in the fighting.