Israel's military has formally admitted that it destroyed a suspected Syrian nuclear reactor in 2007.
It said the air raid in the eastern Deir-al-Zour region had removed "an emerging existential threat to Israel and the entire region".
It said the reactor was close to being completed. It is long been thought Israel was responsible, but it never acknowledged this until now.
Syria has repeatedly denied that the bombed site was a nuclear reactor.
The admission comes after Israeli military censors lifted an order banning officials from discussing the operation.
The International Atomic Energy Agency has said in the past that the site was "very likely" to have been a nuclear reactor.
It has also suggested that it was being built with the help of North Korea.
Syria, which has joined the nuclear Non-Proliferation Treaty, has denied this.
- Israel 'strikes Damascus military complex'
What did Israel's army say?
It released newly declassified materials related to the air raid on 5-6 September 2007.
They included what Israel says was footage of the strike on the al-Kubar facility in Syria's desert region, as well as photographs of the covert operation.
"On the night between 5-6 September 2007, Israeli Air Force fighter jets successfully struck and destroyed a Syrian nuclear reactor in development," the Israeli army said in a statement.
"The reactor was close to being completed."
Israel said four F-16s and four F-15s fighter jets bombed the facility.
"The message from the attack on the nuclear reactor in 2007 is that the state of Israel will not allow the establishment of capabilities that threaten Israel's existence," the statement said.
"This was our message in 2007, this remains our message today and will continue to be our message in the near and distant future."
Israel has recently intensified its warnings over the growing military presence of Iran in Syria.
In February, Israeli jets carried out air strikes on Syrian and Iranian military targets operating inside Syria.
- 'Iran building military base in Syria'