Former IDF chief of staff Gabi Ashkenazi said the world must not remain passive over the Syrian regime’s use of chemical weapons, and that President Bashar Assad himself must be held responsible.

“Doing nothing is not an option,” Ashkenazi said in an interview with CNN’s Christiane Amanpour that was broadcast on Tuesday.

Ashkenazi added that before any action is taken, the prime culprit must be identified as the Syrian leader.

“We have to be clear that it was his decision,” he said.

The former IDF general suggested a range of action, from upping support for rebel groups to imposing a no-fly zone on parts of Syria. Ashkenazi made it clear that the time has come to arm the rebels, a course of action the US is considering and several European countries already support.

“That means providing them with lethal and not just nonlethal assistance — that means weapons — to help them to topple Assad,” he said.

Ashkenazi lamented that more action was not taken in the past as it would, perhaps, have saved lives in the long run of a civil war that has so far cost over 70,000 lives and generated over a million refugees.

“We should have helped them a year ago when there were [only] 10,000 deaths and before the more extremists groups arrived,” he said.

Ashkenazi, who was the IDF’s top officer from 2007 to 2011, said the inevitable downfall of Assad would be a mixed blessing for Israel.

“I think generally speaking from a strategic point of view it is good news,” he said. “It will break the radical axis that runs through Iran and Damascus to Hezbollah and Hamas. It will be a major blow to Iran and Hezbollah.”

“Syria was and still is the logistics hub of Hezbollah,” he added and noted that while funding for the terror group may come from Iran, “the weapons come out of Syrian depots.”

As for growing concerns that the rebel cause in Syria has become a rallying point for a wide range of extremists groups, including those affiliated with al-Qaeda, that are drawing ever closer to the border with Israel, Ashkenazi expressed confidence in Israel’s security capabilities to deal with cross-border threats.

“From an Israeli perspective I think we can deal with it,” he said.

Ashkenazi also gave a guarded response to questions about media reports that in 2010 he refused a request by Prime Minister Benjamin Netanyahu to raise the IDF’s war readiness in preparation for an attack on Iran. The incident was seen as an indication that the security establishment does not back Netanyahu’s bold threats that Israel is prepared to go it alone in a strike on Iran’s nuclear facilities.

“That is factually wrong,” Asheknazi said but would not expand on exactly what transpired at the time, saying only that it was a matter of timing and that, in his opinion, the military option is the last option.

“Unless the sword is against your throat you don’t use it,” he said.

Ashkenazi commented on recent efforts to improve ties with Turkey that became frigid, if not hostile, after IDF commandos stormed the Gaza-bound Mava Marmara ferry and shot dead nine Turkish citizens when they came under violent attack from those on board. Turkey made normalization with Israel dependent on an apology and compensation for the deaths, but the families of those who died have also begun legal proceedings against the soldiers involved. As the then commander of the IDF, Ashkenazi is also on trial in absentia.

“It is important to fix the relationship with Turkey,” he said, adding in reference to the indictments that “it comes with the job of being a general in the IDF.”

Yet, despite the regional threats, Ashkenazi said that Israel’s most pressing problem is that of its own internal divisions.

“I would like the internal dialogue to be back the way it was 30 years ago,” he said.