The most popular Israeli film this year says much about Israel’s ever-contradictory state of mind. “Beaufort,” which opens January 18 as one of the centerpiece films of the 17th annual New York Jewish Film Festival, is an antiwar war movie about courage and cowardice, obedience and rebellion, heroism and survival.

The Hezbollah enemy is never seen. Nor are the Israeli politicians who sent the soldiers portrayed in this powerful film to war in Lebanon first in 1982 and again in the summer of 2006 in a disheartening reprise of the earlier invasion. At the start of Israel’s first invasion — Operation Peace for the Galilee, as the Israeli Defense Forces called its campaign to crush Palestinian Arab guerrillas — the Shiites of southern Lebanon welcomed the Israeli soldiers who would rid them of the Palestinian Arabs who had usurped their land to attack Israel’s northern settlements. But Israel’s 18-year occupation ultimately left more than 1,000 Israelis dead, enflamed the civil war in Lebanon, and created Hezbollah, the militant Shiite “Party of God.”

The full impact of the second, 34-day Israeli incursion in 2006 remains uncertain. But it was clearly time to examine such wars of choice — in Israel, at least, if not yet in America, where none of the anti-Iraq war movies released this year have attracted audiences.

A deceptively simple film, “Beaufort,” which was co-written by Ron Leshem and Joseph Cedar and directed by the latter, is set in 2000 and chronicles the fate of the last combat unit to hold this “Beautiful Fort,” the 12th-century Crusader castle that became a symbol of Israel’s controversial war. The film is already a box-office smash in Israel, and is Israel’s entry this year for the Best Foreign Language Film Oscar. An English translation of Mr. Leshem’s 2005 novel, also titled “Beaufort,” will be published this month by Delacorte. The Hebrew version of the book spent 18 months on Israel’s best-seller list, nine of them at no. 1.

Why such resonance? Timing was clearly a factor. Though “Beaufort” was filmed before Israel’s invasion of Lebanon two summers ago, it was edited as Israeli forces were once again pouring across the Litani River into Lebanon. It had been seven years since Hezbollah and a furious, frustrated Israeli public — spearheaded by four mothers who had sons stationed in Lebanon — had forced prime minister Ehud Barak to withdraw. So searing was the memory of the real Beaufort that Israeli forces had orders during the 2006 invasion to steer clear of the castle.

In 1982, the much contested fortress — the highest point in southern Lebanon, overlooking many of Israel’s northern settlements — was the first major target to be captured by Israeli forces. But the battle by the celebrated Golani special forces brigade against 40 or so Palestinian Fedayeen who held the castle turned out to be unnecessary, since, unbeknown to the attackers, Israeli forces had already advanced beyond the castle. Orders canceling the mission never reached the Golani unit’s commanders.

To celebrate the victory, Israeli prime minister Menachem Begin and defense minister Ariel Sharon flew to the mountain to unfurl an Israeli flag and announce that the fortress had been taken without Israeli casualties. In fact, six soldiers had died and nine others were wounded, among them Major General Moshe Kaplinsky, then the Golani unit’s commander, who recently stepped down as the IDF’s deputy chief of staff. As a result, Beaufort became a metaphor for the detachment of Israel’s political leaders from facts on the ground and eventually for their mismanagement of the entire campaign. In 1997, 73 Israeli soldiers were killed when two IDF helicopters collided in midair while transporting soldiers to Beaufort — the war’s single most deadly incident. In 2000, the isolated outpost at Beaufort was the last to be evacuated and destroyed.

According to Mr. Cedar, the movie’s true subject is not combat but retreat. The film explores fear, specifically how one soldier comes to acknowledge and ultimately accept his own. More broadly, it is an allegory on the trauma that this controversial war inflicted on Israeli society and for the questions Israelis now increasingly ask both about the need for such wars and the nature of their society.

In an arresting scene, the ostensible hero, Liraz Liberti (Oshri Cohen), the unit’s 22-year-old, gung-ho commander, freezes with fear when a fellow soldier, a close friend, is caught in a mortar barrage. “Liraz, get me inside. Liraz!” the wounded soldier pleads for rescue only a few feet away, but beyond the safety of the fortress walls. Liraz, who has been brash and proud in the film’s early scenes, cannot move. His buddy is rescued instead by another member of the unit who braves the mortar fire and drags the wounded compatriot to safety. Neither Liraz nor the rescuer ever speaks of it.

Mr. Cedar said the incident mirrors his own experience when, in 2002, he was summoned back to military service in a call-up that preceded Prime Minister Sharon’s decision to reoccupy the Palestinian Arab West Bank in response to multiple Palestinian suicide bombings inside Israel. Then a new father, Mr. Cedar said, he literally could not move after receiving a computerized call informing him he had six hours to report to his unit’s headquarters.

“I could not lift my arm off the chair,” the director said. “I sat in the dark, utterly paralyzed, until the phone rang again, and another computerized voice said the call-up had been canceled.”

In November 2003, the next and last time he was summoned for reserve duty, Mr. Cedar went to his designated station, but only to tell his commanders that he would not serve. When asked at his hearing why not, “I told them I was afraid,” he said. “That was the bravest thing I have ever done.” Mr. Cedar was jailed for two weeks and exempted from further reserve duty.

Mr. Cedar served in the army as an infantry soldier and medic between 1987 and 1989. He visited Beaufort but was stationed at other posts in southern Lebanon. “I was not a great soldier, but an obedient one,” he said. “I was proud of doing what I was told. By 2003, I realized I was no longer a soldier.” When he read an article in Yediot Ahronot by Mr. Leshem describing a soldier at Beaufort whose fear made him unwilling to risk his life in what he saw as a pointless war, Mr. Cedar was deeply shaken. He and Mr. Leshem met and talked for hours. They decided to adapt the article to film; Mr. Leshem also began working on the novel based on the soldier’s account.

The saga of Beaufort, which Hezbollah steadily shelled until the night Israel left Lebanon, is the antithesis of another of Israel’s founding heroic myths about a mountain: the ancient Hebrews’ outpost at Massada. According to the founding Zionist story, a group of ancient Jewish rebels — men, women, and children alike — committed suicide by throwing themselves off Massada rather than surrendering to the Romans.

“It’s a story that tells us that individual life has no value, that the nation is everything,” Mr. Cedar said. But the Massada myth downplays the other Jews there who were willing to compromise, to give up the mountain and even leave Jerusalem, and hence, lived to tell the tale. It is they, Mr. Cedar said, who preserved Jewish life, values, and culture.

“Zionism’s Massada motto,” he said, “was drummed into us: ‘Better to die as a lion than to live as a dog.’ But the lions of Massada died while the dogs retreated and lived to have puppies. And we’re still around, wagging our tails.”

Hence, the film portrays the retreat from Beaufort not as a defeat, but as an act of strength, of true heroism. To have stayed, the filmmakers argue, would have demanded the pointless sacrifice of Jewish life. Such a theme was bound to be controversial in Israel, and it was. But Israelis, whose films increasingly explore political and moral complexity as opposed to those of the industry’s early years, when unabashed nationalism and invariably heroic patriots dominated Israeli screens, were ready to hear such a harsh verdict. The IDF, in fact, supported the film and the Israeli government helped pay for it.

Israelis, it turned out, were particularly ready to explore the theme of failed war after the second incursion into Lebanon was condemned last April by a national commission led by Eliyahu Winograd. Appointed by Prime Minister Ehud Olmert soon after the war ended, the commission blasted Israel’s top leadership, especially Mr. Olmert, and the military’s leaders. The defense minister, who resigned, lacked “knowledge or experience in military, political, or governmental matters,” the report concluded. Mr. Olmert’s failure was having no “organized plan” when he launched the war, it said, and it accused him of a “a serious failure in exercising judgment, responsibility and prudence.” While the preliminary report stopped short of calling for his dismissal, the prime minister’s approval ratings sank to below 5%.

The mood of the elite audience invited to attend the opening of the film last spring was somber. Israelis fell eerily silent as images of the Israeli outpost atop the craggy promontory near the castle filled the screen. (The movie was filmed not in Lebanon, but at another crusader castle called Kalat Namrud in Israel, not far from the Lebanese border.)

Many in the audience, which included relatives of soldiers who had died or were wounded in Israel, applauded the film, which is highly unusual, and appeared shaken by the film, particularly the men. Among them was General Kaplinsky, who lives with a bullet from the battle for Beaufort lodged in his lung, deemed too dangerous to remove. Among those who had fought for Beaufort, General Kaplinsky was charged 18 years later with overseeing its evacuation. His son had been a member of the Golani brigade in which he had served.

What did he think of the film? I asked him recently in New York. “It was accurate, sometimes painfully so, especially from the soldier’s point of view.”

Was it right to have fought for Beaufort, to have occupied a place for 18 years whose main military value, especially toward the end, was protecting the soldiers who occupied it?

“At the time, I thought it was the right decision, based on what we knew then,” he said carefully, adhering to the Israeli military’s tradition of silence when asked to criticize fellow officers. “We thought that the security zone would collapse if we left, but it had collapsed anyway, though that wasn’t clear to us at the time.” Besides, he added, it was not the army’s decision to leave or to stay in Lebanon. “It was the government’s.”

The commanders had different concerns from their soldiers, he continued, shifting the discussion back to more comfortable ground. “My biggest challenge was trying to motivate soldiers to continue doing a mission that was defined by a timetable,” he said. “If we were leaving 10 months from then, why not tomorrow? Who wanted to be the last Israeli to die in Lebanon?”

He sympathized with American commanders in Iraq, in particular with General David Petraeus, who faced what he called a similar “leadership challenge.”

There were obvious differences both in the wars and in our societies, General Kaplinsky said. For Israel, events in Lebanon posed an immediate threat and challenge. Lebanon and Israel share a border, with the bulk of Israel’s population a mere 200 kilometers away. For America, Iraq was a distant war.

“In Israel, the burden of war is shared by and affects everyone,” he said. Almost every Israeli had a son or a daughter or relative in Lebanon during the first war. And so many others had lost someone because of war or terrorism. In the United States, the burden of war fell mainly on volunteer soldiers and their families.”

But there were some similarities between our nations’ wars, General Kaplinsky suggested by implication. “We had no strategy for victory in Lebanon,” he said. “We could and should have destroyed Fatah’s infrastructure in Lebanon and then immediately pulled out,” he said. “Instead, we stayed almost 20 years, helping create Hezbollah and trying to create a new political order and settle ancient political quarrels among civilians, which armies do not do well. We stayed in what we now call the mud of Lebanon, bleeding.”

General Kaplinski and others argue that the willingness of democracies such as Israel’s and America’s to form commissions such as Winograd to investigate our conflicts and confront mistakes shows the strength of our respective democracies.

But Mr. Cedar is not so sure. Despite the first debacle in Lebanon, the Israeli public, press, and parliament wholeheartedly supported the second war against Lebanon, until it went sour. “That surprised me.”