By STEVEN ERLANGER

PARIS - “War is a beast that needs death, so it doesn’t die itself,” concluded Samuel Maoz, who was thrown into Israel’s war in Lebanon in 1982, at 20, and has now made a disturbing film about what happened to him there. Mr. Maoz, known as Shmulik, was the gunner in one of the first tanks to cross the border into Lebanon in a war aimed at uprooting the mini-state established there by the Palestinian Liberation Organization. It is best remembered, though, for the massacres of Palestinians by Lebanese Christians in the refugee camps of Sabra and Shatila.

Israeli forces did nothing to stop the killing, a moral failure that resounds in Israel today. The film, “Lebanon,” which is in wide release around the world this year, uses that tragedy and the failed war as unspoken historical context. But this is a movie about combat as viewed through a straw, from inside a single tank , as seen by Shmulik (Yoav Donat).

A young man who can’t shoot when ordered to, he suddenly finds that he can, and later, takes over when the tank commander panics. The film, almost entirely autobiographical, is of course about something more: the hunger and shock of war, especially in the first hours of combat, when ordinary teenagers become transformed into soldiers, and killing becomes not just acceptable but a matter of indifference. “There is a metamorphosis, first physical, when you lose your sense of taste, you don’t need to eat, you suddenly hear and see everything sharp and clear,” Mr. Maoz said from his home in Tel Aviv. “When the basic rules of life are not there, you can’t continue thinking with the logic of normal life.

If you do, you’ll probably end up dead. “At the end you don’t fight for your country or your kids, you’re fighting for your life,” he continued. “And if you survive ? and most who died, died in the first day ? after the second day you become a soldier of the war. That’s why the focus is very narrow. ” “Lebanon,” which won the top prize, the Golden Lion, at the Venice Film Festival, is part of a recent wave of Israeli films about the Lebanon war.

“Lebanon was in a way Israel’s Vietnam,” said Gadi Taub, an Israeli historian and novelist. “The Lebanon war split Israeli society because it disrupted the whole narrative by which we understood ourselves.” He added, “It was also, like Vietnam, a failure, which also added insult to injury of a bad conscience.” “Lebanon,” Mr. Maoz’s first feature film, takes place during the first day of the war.

The four-member tank crew interacts with the world through the gun sight; the platoon commander, played by Zohar Strauss; and the radio. The tank is an actor too: powerful, cramped and hot, it serves both as protection and prison. “In the tank,” Mr. Moaz said, “you’re either home in one piece, or there is nothing to bury, and they put stones in the coffin because your father needs to think he’s carrying something.” But the tank also serves to focus the viewer .

“I put you inside the tank, so you identify totally with them, so you see only what they see and know only what they know,” Mr. Maoz said. Mr. Maoz is unsparing about himself and his tank mates (he used their real names ). Anxious about their responses, he gathered them to see the film. Afterward they told him, “Yes, that’s what happened,” he said.

“And I said, ‘So?’ And they said, ‘Let’s go drink something,’ and we spent the next two hours talking about anything else, escaping.” In 2006 Israel went back into Lebanon, in a short, spasmodic and unsuccessful war against Hezbollah. Mr. Maoz was appalled, he said, and felt both helpless and responsible, as children of his friends died there.

“I wanted to change minds, but I couldn’t talk about it in a political way, that just creates resistance. But if you talk to the stomach and the heart, if you can touch the instincts of the mothers . . . ” he said, breaking off. “I’d rather change the hearts of 10 parents than impress 100 journalists.” For Mr. Maoz, now 48, the sense of responsibility for killing remains strong. “There is no escape from it,” he said softly.