KABUL, Afghanistan — Around 20 guests gathered in a dusty corner of northern Afghanistan on Sunday night to break bread in celebration of a miraculous truce: the coming together of two bitter enemies who had been on opposite sides of the war.

The centerpiece of the meal was roasted goat, a sacrifice by a father offered upon the return of his son, for that was what was happening. Just three months before, the host, Abdul Basir, a government militia commander, had fired his rifle in the dark of the night at his son Said Muhammad, a hardened Taliban fighter, and was sad not to have killed him.

Now, after trying several times to fulfill their vows to kill each other, the father and son were embracing and exchanging garlands of plastic flowers in the northern province of Faryab, where their battle had played out.

“He was my son — but he had been a coward out there fighting me,” said Mr. Basir, a lanky, cleanshaven commander in his 40s who has known little but combat since he was 15. Several of his children and five of his brothers serve in his militia. “Now I am very happy that he has returned to us. I hugged him and I said, ‘No matter what you did, you are my son.’”