The son of a leading Hamas figure, who famously converted to Christianity, served for over a decade as the Shin Bet security service’s most valuable source in the militant organization’s leadership …

Mosab Hassan Yousef is the son of Sheikh Hassan Yousef, a Hamas founder and one of its leaders in the West Bank. The intelligence he supplied Israel led to the exposure of a number of terrorist cells, and to the prevention of dozens of suicide bombings and assassination attempts on Israeli figures. …

Yousef’s memoir, “Son of Hamas” … will be released next week in the United States. Yousef, 32, became a devout Christian 10 years ago and now lives in California after fleeing the West Bank in 2007 and going public with his conversion.

Yousef was considered the Shin Bet’s most reliable source in the Hamas leadership, earning himself the nickname “the Green Prince” – using the color of the Islamist group’s flag, and “prince” because of his pedigree as the son of one of the movement’s founders.

During the second intifada, intelligence Yousef supplied led to the arrests of a number of high-ranking Palestinian figures responsible for planning deadly suicide bombings. These included Ibrahim Hamid (a Hamas military commander in the West Bank, Marwan Barghouti (founder of the Fatah-linked Tanzim militia) and Abdullah Barghouti (a Hamas bomb-maker with no close relation to the Fatah figure). Yousef was also responsible for thwarting Israel’s plan to assassinate his father.

“I wish I were in Gaza now,” Yousef said by phone from California, “I would put on an army uniform and join Israel’s special forces in order to liberate Gilad Shalit. If I were there, I could help. We wasted so many years with investigations and arrests to capture the very terrorists that they now want to release in return for Shalit. That must not be done.” …

Only now … is Yousef exposing the secret he kept since 1996, when he was first held by Shin Bet agents seeking to enlist him in infiltrating the upper echelon of Hamas.

Their efforts proved successful, and Yousef was released from prison in 1997. His former handler, who no longer serves with the security service, says Yousef collaborated with Israel because he wanted to save lives.

“So many people owe him their life and don’t even know it,” said the handler, named in Yousef’s book as Captain Loai. “People who did a lot less were awarded the Israel Security Prize. He certainly deserves it.”

Loai makes no secret of his admiration for his former source. “The amazing thing is that none of his actions were done for money,” he says. “He did things he believed in… His grasp of intelligence matters was just as good as ours – the ideas, the insights. One insight of his was worth 1,000 hours of thought by top experts.”

Loai recalled one time when the Shin Bet received information that a suicide bomber was going to be picked up at Manara Square in Ramallah and be given an explosives belt.

“We didn’t know his name or what he looked like – only that he was in his 20s and would be wearing a red shirt,” he said. “We sent the Green Prince to the square and with his acute sense, he located the target within minutes. He saw who picked him up, followed the car and made it possible for us to arrest the suicide bomber and the man who was supposed to give him the belt. So another attack was thwarted, though no one knows about it. No one opens Champagne bottles or bursts into song and dance. This was an almost daily thing for the Prince. He displayed courage, had sharp antennae and an ability to cope with danger. We knew he was one of those who in any situation – rain, snow, summer – give their all.”

With his memoir, Yousef hopes to send a message of peace to Israelis. Still, he admits he is pessimistic over the prospect of Israel signing a peace agreement with the Fatah-led Palestinian Authority, let alone Hamas.

“Hamas cannot make peace with the Israelis. That is against what their God tells them. It is impossible to make peace with infidels, only a cease-fire, and no one knows that better than I. The Hamas leadership is responsible for the killing of Palestinians, not Israelis,” he said. “Palestinians! They do not hesitate to massacre people in a mosque or to throw people from the 15th or 17th floor of a building, as they did during the coup in Gaza. The Israelis would never do such things. I tell you with certainty that the Israelis care about the Palestinians far more than the Hamas or Fatah leadership does.”

We don’t often trust this source, the Israeli paper Haaretz, because it is biased to the left with all that that entails. But this time we believe it.