A section of the Pakistani military top command now agrees with Washington that the country's armed forces should be sent into the North Waziristan area, a sanctuary for al Qaida and Afghan insurgents, analysts and officials said Tuesday.

Due to resistance from the core army, however, any operation there could be half-hearted.

The Obama administration is pressuring Pakistan to follow its offensive against Pakistani Taliban in South Waziristan with a push against Afghan insurgents and al Qaida fighters based in North Waziristan, a territory controlled by the Haqqani network, widely seen as the most dangerous rebel group in Afghanistan.

President Barack Obama said in his West Point speech two weeks ago that the US had "made it clear that we cannot tolerate a safe haven for terrorists whose location is known and whose intentions are clear."

Gen. David Petraeus, the head of the US Central Command, reportedly pressed for action in North Waziristan during a visit Monday to Islamabad, while Adm. Michael Mullen, the chairman of the Joint Chiefs of Staff, is expected to reinforce the demand this week.

"I remain deeply concerned by the growing level of collusion between the Afghan Taliban and al Qaida and other extremist groups taking refuge across the border in Pakistan," Mullen said Tuesday in Kabul, just before leaving for Islamabad.

Afghan insurgent Jalaluddin Haqqani, who now operates through his son Sirajuddin, is viewed as close to the Pakistani military in a relationship that dates 30 years. The Haqqani network is allied with but independent of the Afghan Taliban.

While most experts think that the Pakistani military would never turn on Haqqani, some senior Pakistani security officials privately are advocating a change in policy. The parts of the military that deal most closely with the U.S. seem to be the most convinced that Haqqani no longer serves Pakistan's interests.

"Once we're done with the TTP (Tehreek-e-Taliban Pakistan) we'll go after Haqqani and all the others," said one highly placed Pakistani official, who spoke only on the condition of anonymity because of the sensitivity of the issue. "It is just a question of sequencing." The Tehreek-e-Taliban Pakistan, more commonly called the Pakistani Taliban, are the leading Islamist group in the country.

Among the reasons for growing disaffection with Haqqani are his tendency to support extremist violence, his lack of popular appeal in the majority Pashtun areas of Afghanistan and his broad control over the Pakistani Taliban, whom the Pakistani government has declared an enemy.

The Pakistani Taliban's campaign of terrorism in Pakistan continued Tuesday, when a car bomb killed 33 people in Dera Ghazi Khan, in Punjab province.

Since Pakistan launched its military operation against the Pakistani Taliban in South Waziristan in October, most of the group's fighting force appears to have slipped away, along with its al Qaida allies, to North Waziristan, while a large part are thought to be in Orakzai, another tribal territory.

The presence of Pakistani Taliban in North Waziristan could provide a pretext to send in troops without the military being seen as fighting an unpopular "American war," but tackling Haqqani himself would be a radical departure.

"I do not think that the Pakistani security establishment has made that strategic decision of going against the Afghan Taliban," said Simbal Khan, an analyst at the Institute of Strategic Studies, a government-funded research center in Islamabad. "It is quite likely under U.S. pressure that we'll see some operations in the central part of North Waziristan, but it is not clear that will amount to taking on the Haqqani network."

Also, with many viewing Obama's plan for Afghanistan as an exit strategy, the core of the Pakistani military and public opinion fears making an enemy of Haqqani. He controls Afghanistan's Paktika, Paktia and Khost provinces, a region bordering Pakistan that in hostile hands could create serious trouble for Islamabad. Some Pakistani officials also regard him as "reconcilable," that is, separate from al Qaida.

A limited operation could deploy the military in the middle of North Waziristan, between Miran Shah and Mir Ali, where some al Qaida-linked fighters are thought to have escaped after the army went into South Waziristan. That way, the army could undertake an operation that wouldn't clash directly with Haqqani's fighters.

Up to now, North Waziristan's Taliban extremists, both Pakistani and Afghan, haven't been a threat to Islamabad, as they were focused on fighting in Afghanistan.

In view of Haqqani's influence over the Federally Administered Tribal Area, the lawless border zone between Pakistan and Afghanistan, any assault in the region that spares him also will spare the Pakistani Taliban.

"Virtually all of FATA is under the control of the Haqqani network," said Khadim Hussain, of the Aryana Institute for Regional Research and Advocacy, an independent research center in Islamabad. "If you leave out the Haqqani network and dismantle the rest of them, it won't make much of a difference."

Pakistan has strong reasons not to go after Haqqani, however, among them that the military is becoming dangerously overstretched, with an operation involving some 30,000 troops in South Waziristan, smaller offensives elsewhere in the tribal area and a military commitment to the Swat valley in the northwest, where an anti-Taliban offensive took place earlier this year. Relations also remain tense with archrival India.

Shah is a McClatchy special correspondent.