KHAN NESHIN, Afghanistan  Five-year-old Sadiq was not a casualty of war. He was simply unlucky. The boy had opened a sack of grain at his home early on Wednesday morning, and a pit viper coiled inside lashed up and bit him above the lip.

His father, Kashmir, knew his son was sure to die. With no hospital anywhere nearby, he rushed the boy to an American outpost to plead for help. By midafternoon, Sadiq’s breathing was labored. Respiratory failure was not long off.

The events that followed unfolded like a tabletop counterinsurgency exercise at a military school. On one hand, the United States military’s medical capacity, implanted across Afghanistan to care for those wounded in the war, could not be used as primary care for the nation’s 29 million people. On the other hand, would the officer who upheld this policy be willing to watch a 5-year-old die?

Since last year, Helmand Province has been the scene of the most intensive combat in Afghanistan. Marine patrols and the Taliban fight daily, and helicopters are needed to evacuate the wounded.