Former Israel Defense Forces Chief of Staff Gabi Ashkenazi said on Wednesday that sanctions are the best course of action to use against Iran.

Speaking at a discussion on Israel's counter terrorism triumphs and failures at the Brookings Institution in Washington, Ashkenazi said sanctions against Iran are "less costly than all the other options" while still "keeping all the options on the table."

Earlier this month, Israel's ex-Mossad chief drew fire for saying a military strike on Iran would be a "stupid thing."

Defense Minister Ehud Barak said former Mossad chief Meir Dagan's comments "hurt Israel's ability to deter."

Ashkenazi also discussed Israel's counter terrorism efforts, saying he thinks that a policy of targeted killings works. "The problem is, again, the high price with this clean statement of 'collateral damage'," Ashkenazi said.

On the subject of collateral damage, Ashkenazi criticized Hezbollah and Hamas for fighting from "urban areas", saying "they do it hoping to be immune from being targeted."

"The biggest challenge in fighting terror – it’s how to remain relevant against terror, how to prepare the military to the variety of challenges," Ashkenazi said. "It’s not F-16 or M-16, you need them both."

Reacting to the recent anti-government protests in the Arab world, Ashkenazi said "obviously we want to see democracy from the other side of the border, but first of all, you need to see an accountable address on the other side. It makes it easier to cooperate."