An American-born 22-year-old who served in the Israel Defense Force, Sergeant Michael Levin decided to devote his life to Zionism after reading, as a young boy, his grandfather’s book about surviving the Holocaust.

Levin was killed in southern Lebanon on Tuesday morning, Israeli time, along with two other soldiers, when Hezbollah forces reportedly attacked his platoon with anti-tank missiles.

Levin had moved to Israel after graduating from high school four years ago, and after living temporarily in a kibbutz, he joined the ranks of the IDF, hoping to one day become the chief army commander’s bodyguard.

Levin’s family — including his parents, his older sister Elisa, and his fraternal twin Dara — left for Jerusalem yesterday afternoon for the funeral, which will be held today at Mount Herzl military cemetery. A memorial service at Levin’s family synagogue near Philadelphia will take place on August 7.

“His grandfather’s book was the main thing that turned his life around,” his close friend, Baruch Ganz, said yesterday. “He saw the problem of the Holocaust, and he saw how that repeated itself in history. He saw the Zionist dream as a potential answer to that — a place where Jews could rest as one in one land, that could be their own and that could be defended.”

From a young age, Mr. Ganz said, Levin wanted to spend his life defending Israel. According to Rabbi Jeffrey Schnitzer, who taught Levin in Hebrew school for two years, Levin was just 16 when he declared his intention to move to Israel and join its army. His parents tried gently to dissuade him, suggesting instead that he go to college, but his mind was set.

“That was the end of that,” Rabbi Schnitzer, who informed the family of Levin’s death on Tuesday, said. “It’s not that they didn’t want him to go, but they were concerned for his safety. At one point, his dad said, ‘What if I hide your passport?’ He said, ‘I’ll get there anyway, and you can’t do anything to stop me.'”

“He was a guy who would rather debate you to death than anything,” Rabbi Schnitzer warmly recalled. “When he was 14 or 15, we would go back and forth with the Talmud. I would say, ‘This is the accepted practice. This is what we do!’ And he’d be adamant that this was not the correct way to behave. That’s the way he was.”

Donny Miller, who lived on Levin’s block in suburban Philadelphia for most of his life, got to see him in Tiberias about a week earlier, as he happened to be in Israel with his mother for his brother’s 30th birthday party.

“I was scared s—less to go visit him,” Mr. Miller said last night from Israel. “I was told by countless people not to go up, not to be stupid. But I knew he wouldn’t put me in harm’s way, so I went up to see him. We hung out. I met his platoon. They were like a family. He said, ‘I have their backs, and they have mine.'”

After the brief visit, Mr. Miller said, Levin said he had to go back to work and showed him to the bus station.

“I gave him a hug. I gave him a kiss. I told him I loved him. I told him to be careful,” Mr. Miller said. “He walked one way. I walked another.”

Not long after, Levin’s platoon was sent into Lebanon.

His family last saw him just five days ago, when he was at home for vacation. According to one neighbor, Levin had not told his family that he would be coming and surprised them by somehow packing himself into a box on the doorstep and ringing the bell.

When news came that Hezbollah had kidnapped two Israeli soldiers, Levin told them he would have to cut his visit short and return to his platoon.

Mr. Ganz, who served in the IDF between 2003 and 2005, said yesterday that Levin’s death had left his many friends devastated — that young men and women were walking the streets of Jerusalem “with tears down their faces, asking why.”

Assuming his father will allow it, Mr. Ganz said, he plans to add Levin’s Hebrew name — Melech, which means “king” — to his own at the memorial next week.