A few weeks earlier, I had another virtual encounter with the evanescent sheik, in a rented house on the prosperous outskirts of Faisalabad, a city that lies, like Abbottabad, a few hours’ drive from Pakistan’s tribal frontier. Forty-eight hours earlier, the house had been the target of a raid led by the F.B.I. and the C.I.A. that captured Abu Zubaydah, the fourth-highest-ranking Qaeda leader — after Bin Laden, his Egyptian deputy Ayman al-Zawahri and Khalid Shaikh Mohammed, the operational mastermind of 9/11.

Abu Zubaydah, who was shot in the raid, was later one of three men, including Mr. Mohammed, to be waterboarded by the C.I.A. without volunteering anything about the whereabouts of Bin Laden. But I have often wondered — as I did again, after seeing the photographs of the scruffy, boarding-house-looking interior of the house the Seal team raided in Abbottabad — about the roster of Arab names that had been chalked up in the Faisalabad kitchen assigning mealtime duties. Among them, intriguingly, was the single word, “Osama.”

Reviewing all this over recent days, my thoughts have gone back, as much as anywhere, to that one-and-only direct encounter in 1989. In light of what transpired at Abbottabad, several things stand out:

First, the fact that access to the camp lay through a C.I.A. contact involved in America’s financing and arming of the mujahedeen; Bin Laden and his cohorts were then, at least notionally, America’s men. Second, Bin Laden’s hostility toward the United States, manifested by his sullen demeanor in the presence of an American reporter. Third, the close liaison, then and later, between the jihadis and the ISI, Pakistan’s spy agency, which acted as a conduit for American and Saudi backing of the mujahedeen.

For the moment, attention is focused on nagging questions about the raid: whether, without a weapon in his hands, Bin Laden might have been taken alive; and whether, with the man now dead, he will prove a lasting icon for Al Qaeda and its affiliates, or, with his leadership extinguished, the movement will become a growing irrelevance, at least in the politics of the Arab world, amid the democratic currents now inspiring the Arab Spring.

Along with these, and perhaps most pressing in its implications for America’s relations with Pakistan, the war in Afghanistan and the struggle with Al Qaeda, there is a further question: whether the ISI knew all along that Bin Laden was “hiding in plain sight” — for as long as five years, as his wounded Yemeni wife is said to have told Pakistani interrogators — in a town, Abbottabad, that is one of Pakistan’s principal army garrisons.

Making sense of the jumble of justifications from senior Pakistani officials is a fool’s errand. Some have said Bin Laden’s presence in Abbottabad took the country’s security establishment by surprise; others, including at least two former ISI chiefs, say it is inconceivable that the spy agency did not know. Still others have said that Bin Laden’s success in hiding in a city in Pakistan’s interior was the result of basic mistakes by Pakistan or, conversely, that it can be traced to America’s decision not to share with Pakistan the intelligence that led to pinpointing Abbottabad as ground zero of the manhunt.

Pakistan’s double-dealing is hard to contest. The country has absorbed more than $20 billion in American and other Western aid since 9/11, a crucial buttress to its fragile economy, yet it has been “looking both ways,” in the words of Britain’s prime minister, David Cameron, on the terrorism spawned on its soil and across the border in Afghanistan. A WikiLeaks release of military field reports last year offered new evidence of the ISI’s role as a patron of Pakistan-based Taliban groups, and Al Qaeda. While few would have imagined its complicity might extend to sheltering Bin Laden, Pakistan’s trustworthiness as an ally has long been questioned in Washington.