By DECLAN WALSH
LONDON — When he leaves his post on Friday, Gen. Ashfaq Parvez Kayani, the inscrutable Pakistani Army chief and former spymaster, will end a nearly decade-long chapter as the focus of American fears and frustrations in Pakistan, the reluctant partner in a contentious and often ill-tempered strategic dance.
Suspicious American officials frequently accused him, and the 600,000-member army he led, of double-dealing and bad faith: supporting the Afghan Taliban, allying with militant groups who bombed embassies and bases, and sheltering Osama bin Laden.
Those accusations were made in private, usually, but exploded into the open in late 2011 when Adm. Mike Mullen, the American military chief who sought to befriend General Kayani over golf and dinners, issued an angry tirade to Congress about Pakistani duplicity.
The taciturn General Kayani weathered those accusations with a sang-froid that left both allies and enemies guessing about what, or whom, he knew. But few doubted that he nursed grievances, too — about C.I.A. covert operations, the humiliating raid that killed Bin Laden, and perceived American arrogance and inconstancy.
General Kayani, 61, steps down with those arguments still lingering. And reckoning with his legacy exposes a cold truth at the heart of the turbulent American-Pakistani relationship: that after years of diplomatic effort, and billions of dollars in aid, the countries’ aims and methods remain fundamentally opposed — particularly when it comes to the endgame next door in Afghanistan.
“We have almost no strategic convergences with Pakistan, at any level,” admitted a senior American defense official. “You’ll never change that, and it’s naïve to think we can do it with an appeal to the war on terror.”
Seen through Pakistani eyes, however, General Kayani was a more tangible, even positive, force. Despite his personal antipathy for the country’s civilian leadership, he restrained army meddling in politics and tolerated increased criticism in the news media. After the country’s first successful completion of a democratic election cycle, Pakistanis can dare to imagine that a long era of military coups might be over.
Further, he was at least partly successful in refocusing the army’s monomaniacal attention on India, the old enemy, toward a new threat posed by the militants lurking in the country’s remote areas.
Still, in other respects, Pakistan’s bullying military class has remained unchanged, particularly in its dismal record on rights abuses. General Kayani’s soldiers and spies have prosecuted a dirty war against separatists in Baluchistan Province, cultivated contacts with sectarian militias, and intimidated and bloodied rights campaigners and journalists.
For all that, his authority was never seriously challenged. “He’s one of the most powerful generals Pakistan has ever had,” said Vali R. Nasr, the dean of the Johns Hopkins School of Advanced International Studies.
Now, as he hands off to his successor, at a time of diminishing American engagement in the region, the largest question about the enigmatic general is how much of that legacy will endure.
In many ways, General Kayani was the antithesis of the swaggering general and junta leader he succeeded, Gen. Pervez Musharraf, and his mandate after taking the top army post in 2007 was to repair the prestige that was tarnished under General Musharraf’s watch. He has been quiet and philosophical where General Musharraf was loquacious and boastful. Foreigners complained that his reserve could be unnerving, and that he mumbled. In meetings, he sat like a perched eagle, occasionally darting out for a cigarette.
Those who knew him well said his public reserve was simply a tactic: In private, with small groups he trusted or needed, he could be blunt and forceful.
“He was the anti-Musharraf,” said Shuja Nawaz, the author of “Crossed Swords,” a history of the Pakistani Army.
But the rise of the Pakistani Taliban posed an immediate challenge. The Taliban’s drive to destroy the security forces and central government shook the Pakistani military’s jihadist sympathies, through unprecedented violence: the beheading of soldiers, the assassination of senior generals, and even suicide bombings against the feared military spy agency, the Directorate for Inter-Services Intelligence, or ISI.