Israel has been “absolutely certain” for many months — long before the alleged August 21 chemical weapons attack that prompted the current Syria crisis — that President Bashar Assad was using chemical weapons in the civil war, the Israeli army’s top intelligence analyst said in an interview broadcast Saturday.

Brig. Gen. Itai Brun, the senior analyst in the IDF’s Military Intelligence hierarchy, said the Israeli army had an extremely effective intelligence-gathering capacity on Syria, but declined to go into specifics.

That capacity, he indicated, allowed Israel’s intelligence chiefs to assert with high confidence that there was only a ‘low probability” that the Assad regime would attempt to fire chemical weapons into Israel in the event of international intervention in the civil war.

In the rare interview, which coincided with the 40th anniversary of the 1973 Arab-Israel War — known in Israel as the Yom Kippur War — Brun said it was “almost impossible” that Israel could be hit by a surprise enemy attack at it was in that conflict, in which 2,500 Israeli soldiers were killed.

Awareness that Israeli army intelligence had failed to predict the Arab armies’ attack on the most solemn day in the Jewish calendar, Brun said, “accompanies me every day.” He said the failure by his predecessors was a function of their limited imagination and the fact that they were “welded to a conception” that Egypt was too weak to attack Israel and that Syria would not attack without Egypt.

Nowadays, the IDF carried out war games, had special teams that questioned assumptions, worked on all kinds of scenarios, and took a range of other measures designed to ensure that the country could not be surprised again, he said.

It was Brun who, in April, delivered a bombshell lecture in which he declared publicly that Assad was using nerve gas against rebel forces: “To the best of our professional understanding, the regime has used lethal chemical weapons,” he said in late April, and specified that the IDF believed the toxic element was Sarin. He noted then that it had been used on more than one occasion, including in an attack on March 19.

His assertion was initially queried, but subsequently accepted, by US and other officials. The Israeli conclusion was “based on very special work,” by a team that “saw very clearly,” Brun said on Saturday.

In his April address, Brun showed a photo of a child with narrowed pupils and foam coming out of his mouth. Both of these were indicative of a nerve agent, he said. He repeated those indicators in the Saturday interview, broadcast on Israel’s Channel 2 news, while making plain that the IDF had other, more conclusive, sources of information.

Israeli military intelligence reportedly played a key role in providing evidence of Assad’s chemical weapons use in the August 21 attack that sparked the current crisis over Syria. On the Friday after that attack, Channel 2 reported that the weapons were fired by the 155th Brigade of the 4th Armored Division of the Syrian Army, a division under the command of the Syrian president’s brother, Maher Assad. The nerve gas shells were fired from a military base in a mountain range to the west of Damascus, the TV report said.

The report did not state the source of its information. But subsequently, Germany’s Focus magazine reported that an IDF intelligence unit was listening in on senior Syrian officials when they discussed the chemical attack. According to the Focus report, a squad specializing in wire-tapping within the IDF’s prestigious 8200 intelligence unit intercepted a conversation between high-ranking regime officials regarding the use of chemical agents at the time of the attack.