General Ashfaq Kayani is backing dialogue partly due to fears that the end of the US combat mission in Afghanistan in 2014 could energise a resilient insurgency straddling the shared frontier, according to commanders deployed in the region.
"There was a time when we used to think we were the masters of Afghanistan. Now we just want them to be masters of themselves so we can concentrate on our own problems," said a senior military officer stationed in South Waziristan, part of the tribal belt that hugs the Afghan border.
"Pakistan has the power to create the environment in which a grand reconciliation in Afghanistan can take place," he said, speaking in the gritty town of Wana, about 30 km (20 miles) from Afghanistan. "We have to rise to the challenge. And we are doing it, at the highest level possible."
On December 7, Kayani hammered home his determination to support a negotiated end to the war in Afghanistan at a meeting of top commanders at the army headquarters in Rawalpindi.
"He (Kayani) said Afghan reconciliation is our top priority," said a intelligence official, who was briefed about the meeting.
Major progress with Kayani's help could enable US President Barack Obama to say his administration managed to sway Pakistan - often seen as an unreliable ally - to help achieve a top US foreign policy goal.
Nevertheless, diplomats in Islamabad argue that Pakistan has begun to show markedly greater enthusiasm for Western-backed attempts to engage with Taliban leaders. Western diplomats, who for years were sceptical about Pakistani promises, say Islamabad is serious about promoting stability in Afghanistan.
"They seem to genuinely want to move towards a political solution," said an official from an EU country. "We've seen a real shift in their game-plan at every level. Everyone involved seems to want to get something going."
'PAST MISTAKES'
Kayani seemed to signal that the army's conception of its role in Pakistan and the region was changing in a speech to officers in Rawalpindi last month.
"As a nation we are passing through a defining phase," Kayani said. "We are critically looking at the mistakes made in the past and trying to set the course for a better future."
Outsiders are largely barred from the tribal belt, but Reuters was able to arrange a rare three-day trip with military last month.
Security appeared to have improved markedly in South Waziristan since the offensive, but the visit also underscored the huge task army still faces to gain control over other parts of the border region.
Haji Taj, who runs an seminary for boys and girls in Wana, said militants were still at large in surrounding mountains. "Outside the army camp, it's Taliban rule," he said.