In short:
The Israel Defense Forces (IDF) has revealed it sent more than 100 troops into Syria in September, months before the Assad regime fell, to target a massive underground missile factory.
Israel says the facility near Maysaf, in Syria's west, was supported by Iran and had started to make missiles for its allies such as the Lebanese militant group Hezbollah.
The Assad regime's rule of Syria dramatically collapsed in December after rebels mounted a lightning offensive through the country.
Israel has revealed it sent troops into Syria months before the Assad regime fell, launching a night time mission to target a massive underground missile factory which it said was funded and supported by Iran.
The Israel Defense Forces (IDF) published new information about its September 8, 2024 raid, which it said was promoted by missile manufacturing beginning at the facility near Maysaf in western Syria.
IDF spokesman Lieutenant Colonel Nadav Shoshani said Israel had been monitoring the site's construction for years, and acted when it posed an "imminent and active threat".
"This facility was the flagship of the Iranian manufacturing efforts in our region," he told a briefing on Thursday, local time.
"They were planning on assembling and manufacturing different types of precision guided long-range missiles — some of them up to 300 kilometres.
"It was active, high-speed manufacturing of hundreds of precision guided missiles a year, in this manufacturing site in western Syria, close to the border with Lebanon."
Israel's military says it had been monitoring the site's construction for years prior to its destruction. (Supplied: Israeli Defence Force)
A number of Israeli media outlets had reported details of the raid in recent times, and it is unclear what has prompted the IDF to publicise its mission now.
The Syrian Observatory for Human Rights war monitor had previously reported that 27 people were killed in the raid.Â
The Israeli military did not disclose any casualty figures.
The Observatory said the facility was created and supervised by Iran's Revolutionary Guards.
Lieutenant Colonel Shoshani said Israeli intelligence showed construction of the factory started in late 2017, and finished four years later, with Iranian missile manufacturing machinery installed after that.
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He insisted a ground operation was necessary given its depth underground, meaning air strikes would not be effective.
Commandos sent into the site were flown in on helicopters, with Israeli fighter jets and drones clearing the way for the operation.
Israel has long accused Iran of providing weapons, munitions and funding to the Lebanese militant group Hezbollah.
At the time of the raid, Hezbollah was firing missiles and rockets into Israeli territory, and the IDF was launching strikes into southern Lebanon and beyond.
The lieutenant colonel said documents had been seized from the site, including handbooks on missile manufacturing.
Bashar al-Assad is living in exile in Russia after the overthrow of his Syrian regime. (ABC News: Haidarr Jones)
Since the Assad regime fell in December, Israel has been criticised for launching dozens of air strikes across the country.
It was targeting what it said were weapons facilities and stockpiles of the former government's forces, insisting it did not want them to fall into the hands of the rebel forces which swept to power.
Israel has also faced international demands to withdraw troops and tanks from Syrian territory, after deploying forces across the border from the Israeli occupied Golan Heights into a former buffer zone which had been in place for five decades.