The day before he was killed in his home by a visitor with explosives hidden in his turban, Burhanuddin Rabbani was in Tehran, urging the world's top Islamic scholars to take a stand against suicide bombing.
Mr. Rabbani implored the gathering of 700 Islamists – including envoys from Hamas, Hezbollah and Islamic Jihad – to stop killing their fellow Muslims because it was an insult to their religion.
"Especially in our country, there are a number of individuals who kill Muslims in the name of Muslims. We should take a clear stand against this new phenomenon when the killing of Muslims is seen as something allowable," said Mr. Rabbani, a former jihadist and Afghan president who, for the past year, had sought in vain to negotiate with insurgents as head of Afghanistan's High Peace Council.
Mr. Rabbani's fears proved prophetic. The next day he became the victim of the violence he deplored when a suicide bomber, brought to his home by Rahmatullah Wahidyar, a former minister of the Taliban government, embraced him before blowing himself up. The blast killed Mr. Rabbani, four of his guards and another peace adviser.
The brutal assassination has sent fresh shock waves across Afghanistan just over a week after insurgents launched a brazen attack on the United States Embassy compound in Kabul.
In some ways, however, the killing of Mr. Rabbani was felt more profoundly, because it violated pashtunwali, the unwritten code of conduct that governs so many aspects Afghan life.
This time, the killers weren't targeting symbols of Western power, nor were they hunting a corrupt Afghan politician. Mr. Rabbani, about 70 years old, was an Islamic scholar, a devout Muslim who was killed by a guest he had welcomed in good faith inside his home.
"I cannot believe his killers were Afghan," said Shukria Barakzai, an Afghan lawmaker whose husband happened to be on the same plane as Mr. Rabbani, when he flew from Dubai to Kabul the day he was killed.
"In our culture when someone comes to your home – even if they are the enemy – you are both safe," she said, sobbing. "These killers don't believe in Afghanistan. No, they are sick."
While Mr. Rabbani's assassination is dramatic because of his prominence, it underscores a broader reality in Afghanistan, where 80 per cent of civilian deaths are caused by insurgent attacks; "Muslims killing Muslims," as Mr. Rabbani had put it.
It is also evidence of an upsurge of fighting, which is happening as 100,000 U.S. troops start to withdraw from the country, where they waged an gruelling 10-year long war. The prospect of Western forces leaving by the end of 2014 has stoked fears among Afghans of a new civil war.
Against that backdrop, militants have become emboldened, increasingly targeting Kabul with high-profile attacks that seem to underscore the difficulties of achieving the kind of negotiated settlement with the Taliban that Mr. Rabbani sought through the High Peace Council – an effort that was admittedly failing.
"He was honestly ready to resign, he was so frustrated. He said the Taliban are not ready for peace," noted Waheed Mozdah, an independent analyst in Kabul and former member of the Taliban government.
"The Taliban never talked to this Council. They dismissed it as an American-made jirga," he added, using a Pashtun word for council.
The Haqqani network, which operates from a sanctuary in Pakistan, was blamed for the assault on the embassy compound, as American and Afghan officials sought to depict the criminal network and broader Taliban movement as distinct entities.
However, analysts say such divisions are overstated; that the hardline Haqqanis are not a breakaway movement, but rather, are loyal to Mullah Omar, the Taliban's spiritual leader.
The attack on Mr. Rabbani seemed unrelated to the Haqqanis. Mr. Wahidyar, the former Taliban minister who escorted the suicide bomber, had fought alongside Mr. Rabbani against the Soviets and was not a known associate of the family.
Neither he, nor his associates were searched when they entered Mr. Rabbani's home. It was a customary gesture of trust.