Israel would not withstand a regional conflict ignited by an Israeli strike of Iran's nuclear facilities, former Mossad chief Meir Dagan said on Wednesday, adding that Israel did not have the capability to stop Tehran's nuclear ambitions, just to delay them.

In his first public appearance since leaving the post in September, Dagan said earlier this month that the possibility a future Israel Air Force attack on Iranian nuclear facilities was "the stupidest thing I have ever heard."

Open gallery view Ex-Mossad chief Meir Dagan Credit: Yael Tzur

Speaking during a conference in Tel Aviv on Wednesday, Dagan continued his public rejection of a military move against Iran, saying that Israel didn't "have the capability to stop the Iranian nuclear program, only to delay it."

"If anyone seriously considers [a strike] he needs to understand that he's dragging Israel into a regional war that it would not know how to get out of. The security challenge would become unbearable," Dagan said.

The former Mossad chief reiterated his position, saying that the "military option is the last alternative, not preferred or possible, but a last resort. Every other alternative must be weighed before the use of force."

Referring to those who criticized him for speaking out on these matters soon after his retirement, Dagan said: "I feel obligated to express my opinion on certain matters. The prime minister and defense minister are the ones in charge, but sometimes good sense and a good decision don't have anything to do with being elected."

The former Mossad chief also referred to stalled peace talks with the Palestinian Authority, saying he felt Israel should take the initiative instead of being forced to deal with a less favorable situation.

"I think there should be diplomatic initiative with the Palestinians. They're here and a settlement should be reached with them. If we won't offer things and wait we may have to face a reality in which things are forced on us, and when choosing between initiative and coercion, I prefer initiative," Dagan said.

Referring to the upcoming Fatah-Hamas unity cabinet, Dagan said that Israel was "in a very problematic moment. The link between Hamas and the Palestinian Authority presents complex dilemmas. We need to wait until the dusk settles over this relationship. This alliance is not a historical one."