Dera Ismail Khan, Pakistan ? For Pakistan’s army, ejecting militants from safe havens near the Afghan border has proven to be the easy part. The problems come later: The guerrillas creep back and carry out attacks. Civilians never return.

Pakistani troops walk on a hilltop post Nov. 17, 2009, near Ladha, a town in the Pakistani tribal region of South Waziristan along the Afghan border. For Pakistan's army, ejecting militants from safe havens near the Afghan border has proven to be the easy part. The problems come later: The guerrillas creep back and carry out attacks. Civilians never return.

This is especially true in South Waziristan, where some 30,000 ground troops launched an offensive a year ago, quickly clearing what had been a major hub for al-Qaida and the Taliban. But over the last week, insurgent attacks have killed eight soldiers, while the Pakistani region’s 400,000 people will not return until next spring at the earliest.

“I want to go back but there is no peace,” said Abdul Karim, a 46-year-old goat and cow herder with three children. “I would get stuck between the army and the Taliban,” Karim said as he lined up with other refugees for a cash handout in this dusty town close to South Waziristan.

The problems in South Waziristan — similar in many ways to those facing American troops in Afghanistan — may help explain Pakistan’s reluctance to launch a similar operation in the adjoining North Waziristan region despite pressure from Washington.

Islamabad’s refusal to move into the north, where a powerful militant faction behind many of the attacks on U.S. troops in Afghanistan is based, is raising tensions with Washington, which wants to pressure Afghan insurgents and create conditions for peace talks to end the 10-year war.

U.S. military leaders have acknowledged that the Pakistan army is stretched. But Islamabad is also widely believed to be holding back from North Waziristan because the Afghan Taliban factions there are seen as potential allies when U.S. troops withdraw from Afghanistan.

In Washington on Friday, U.S. Secretary of State Hillary Rodham Clinton laid out a five-year, $2 billion military aid package for Pakistan, an effort to reassure the country of America’s long-term commitment to its military needs as well as boost its efforts against militants.

The U.S. has praised the army’s efforts in the northwest, but a White House assessment this month contained some blunt criticism. It reported that soldiers in South Waziristan were not attacking militants who were returning from the north, where many fled before or during the offensive.

It said the army had been unable to implement the “hold and build” phase of the offensives in South Waziristan and other tribal regions its forces had entered over the last 2 1/2 years — such as Bajur, Mohmand and Orakzai. “Its inability to overcome those challenges could eventually turn last year’s operational successes into stalled strategic efforts,” the report said.

In a sign of those problems, a bomb killed six soldiers Friday in Orakzai, a region where just four months ago the army chief had declared victory. Hours later, Pakistani helicopters pounded targets there and in neighboring Kurram, killing 22 suspected insurgents, government officials said.

In the colonial period, the British army lost hundreds of soldiers to tribesmen in South Waziristan and was never able to subdue the mountainous region, where keeping troops supplied is a costly and difficult exercise.

Soon after Pakistan launched its offensive last year, the Taliban said they were withdrawing to fight a guerrilla war.

An estimated 1 million people have been displaced by Pakistani army operations against militants in the northwest. But unlike many who live in camps, most members of the Mehsud tribe that populates South Waziristan are staying with relatives in the border towns of Tank and Dera Ismail Khan.