AP Photo

The last time somebody tried to make a deal with the Taliban to end the war in Afghanistan, he didn’t get far.

It was the summer of 2008. King Abdullah of Saudi Arabia asked an intermediary to carry a personal request to Mullah Mohammed Omar, the Taliban leader, according to a diplomat in Kabul with knowledge of the negotiations.

The Saudi king asked Mr. Omar for a signed letter disavowing Al Qaeda, whose leaders, Osama bin Laden and Ayman Al-Zawahiri, are believed to be living in Pakistan under the Taliban’s protection.

“The Taliban never came — and they never brought the letter,” said the diplomat, who spoke on condition of anonymity. A former Taliban leader, Arsalan Rahmani, confirmed the diplomat’s account.