1st Lt. Michael Molczyk had heard stories about “insider” attacks — and the Afghan soldiers and police officers who grew to see their partners as enemies. As a platoon commander, he couldn’t ignore those assaults on American troops, which during bad weeks were reported day after day.

But to him, he said, the stories sounded like news from a different planet. In Molczyk’s corner of eastern Afghanistan, uniformed Afghans had saved American lives time and again. They had developed a brotherhood with their U.S. partners that felt earned and unassailable.

Last month, NATO commanders advised troops to take precautions against potential traitors — and Molczyk did — but their concerns felt irrelevant in Paktia province’s Jaji district, he said.

“We’ve been in firefights together. We’ve frozen to death together,” he said in a phone conversation. “Our relationship has been so strong.”

And no relationship mattered more to Molczyk than his partnership with Jalaluddin, the head of the Afghan police in Jaji district who, like many Afghans, goes by only one name.

So when Molczyk’s unit recently got a late-night call from Jalaluddin, they picked up right away. Jalaluddin’s cousin, Noor, had been shot at a family wedding by a suspected insurgent. He was losing blood, and the local hospital couldn’t tend to his traumatic injury: a bullet wound in the ribs.

“We told him to come right over,” Molczyk said. Jalaluddin rushed his cousin to Combat Outpost Herrera, a small U.S. base in the middle of an enemy stronghold.

Soldiers carried the wounded man to the medical tent, where three medics assessed the damage. There was heavy blood loss. Even with a transfusion, Noor might die.

Molczyk was right outside the tent, listening. He knew Noor had probably been targeted because of his family’s close relationship to the U.S. military and Afghan security forces — his brother was also a police officer. Noor’s death would be a blow to them all.

“We need A-positive blood,” Molczyk heard the medic say.

Although it’s a common blood type, no one in the vicinity of the tent was A-positive — except Molczyk. He went inside, took his shirt off and offered his arm, tattooed with the words “Audentes fortuna juvat,” a Latin phrase meaning “Fortune favors the bold.”

But the medic rebuffed him, arguing that a platoon commander couldn’t afford to be weakened by donating blood.

“He told me that I couldn’t because I was combat active,” he said. “I told him I wanted to do this.”

Molczyk prevailed. Within minutes, his blood would revive Noor enough that he could be evacuated to a larger base.

“He came back from the end of his life,” Jalaluddin said in a separate phone conversation.

Although donating blood is routine in the United States, it is rare in Afghanistan and, for many, an act of magic.

It happened just days before Molczyk’s company was to leave the country: After they had purchased a goat as a wedding present for Jalaluddin. After the Americans assumed they had gotten as close to the Afghans as they could. After Molczyk’s men teased him that he was going to cry when it came time to say goodbye to Jalaluddin — which he thought he might.

After the blood transfusion, Jalaluddin approached Molczyk. “Now we are really brothers,” he said.

Jalaluddin had worked with Americans long enough to know that brotherhood is forged through such moments. He tried to convey that to Molczyk through an interpreter.

What he didn’t tell him was that he had seen Afghan-American relationships devolve at the same speed. Like the time one of his best officers got into a shouting match with an American soldier during Ramadan a few years ago, after the soldier cursed at his Afghan partner, Jalaluddin said. Finally, the Afghan officer drew his gun and fatally shot three U.S. troops — an early and devastating green-on-blue attack.

“It was a one-time thing. It was spontaneous. He was a great guy — one of our best officers,” Jalaluddin said. “And he became a killer.”

How to reconcile those two moments — the peak and nadir of relations with the Americans, both emerging suddenly and without notice? It made no sense to Jalaluddin.

The longer he worked with the Americans, the more he liked them. He was serious when he called Molczyk a brother. But he couldn’t shake the thought that a single misunderstanding such as the one he had witnessed could shatter a relationship that felt intimate and important.

"We have the same mission, the same aims,” he said. “We are both willing to die for each other.”

Noor is recovering at an Afghan military hospital. Afghan and U.S. forces are searching for the man who tried to kill him.

Meanwhile, another U.S. unit has arrived in Jaji to replace Molczyk and his men.

“They seem like good guys,” Jalaluddin said. “I hope we can continue the strong relationship that we had with the last group.”