Israel cultivated a member of Syrian President Bashar al-Assad’s entourage, then helped him defect, author Gordon Thomas reveals.

The double agent, code-named “Hassan bin-Ali,” eavesdropped on conversations outside Assad’s office. In 2013, he witnessed a Hamas delegation from Gaza asking the dictator for chemical weapons.

“They would launch them from inside the Jordanian border into Israel, either after being inserted in rocket warheads or dropped in barrels into the Dead Sea and floated across to the Israeli shore,” Thomas writes.

Israel smuggled out bin-Ali, who was allowed to live in the West Bank.

Israeli officials brought his testimony to Jordan. Thomas quotes Jordan’s foreign minister, Nasser Gudheh, as saying Syria “is undoubtedly ruled by a war criminal willing to support terrorists.”

But Jordan feared any move against Syria would result in reprisals from Russia and Iran. Although officials promised to reinforce its border patrols, it would not attack Hamas or Syria.

Israel would act on its own.

Flotilla 13, the country’s elite naval commandos, removed several large rocks they had dug up from islands off Syria’s port city of Latakia, Thomas says.

They hollowed them out and stuffed them full of tracking and surveillance systems, then returned them to the islands. They were used to monitor a nearby chemical-weapons facility identified by bin-Ali.

Thomas writes that those messages were transmitted to an Israeli satellite and analyzed at “a control command center near the Israeli side of the Dead Sea.”

“A week later, people living on the eastern outskirts of Latakia were awoken at night by the sudden explosion near the village of al-Samiyah,” Thomas writes.

“The London-based Human Rights Organization announced that the explosion had ‘completely destroyed a mysterious bunker’ near the village . . . The London-based Arabic newspaper, Al-Hayat, speculated that the missile which destroyed the bunker had been launched from an ‘Israeli submarine with the agreement of the United States.’”

Moshe Ya’Alon, Israel’s defense minister, said: “Israel is forced to defend its vital national interests. We have a set of red lines in regard to our national interest, and we keep to them.”