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.”