What episode features the planet Neural and villagers called the Hill People?

“A Private Little War” is the Star Trek episode featuring the planet Neural and its Hill People.

In the story, Captain Kirk returns to Neural, a primitive world he previously visited. He and Spock discover that the planet’s villagers have acquired firearms and are attacking the Hill People, including Kirk’s old friend Tyree. The Enterprise crew eventually learns that the Klingons supplied the villagers with weapons, disrupting the planet’s development.

Kirk faces a moral and strategic dilemma. Because the Prime Directive forbids the Federation from openly interfering with Neural, he initially resists using advanced technology. Once Klingon intervention has already changed the balance, Kirk decides that the Hill People must receive comparable weapons. The decision turns a local conflict into an arms race.

The episode first aired in 1968 and is widely read as an allegory for the Vietnam War and Cold War proxy conflicts. Viewers sometimes remember Neural as an on-screen spoken name, but the planet’s name appears in the script and episode documentation rather than being clearly spoken in the broadcast.