Prime Minister Stephen Harper met Israel's Prime Minister Benjamin Netanyahu at the United Nations Sept. 21. Netanyahu will be on Parliament Hill next Friday, March 2. (Ryan Remiorz/Canadian Press)

Israel's former national security adviser, also a seasoned ex-spy, says Stephen Harper has offered an eloquent, perceptive assessment of the threat posed by a nuclear-armed Iran.

The prime minister has faced criticism in some circles for amplifying the drumbeats of war with Iran for repeatedly saying the regime would not hesitate to use nuclear weapons and that it poses a "grave threat to peace and security."

Harper's assessment is "eloquent," said Uzi Arad, a former national security adviser to Israeli Prime Minister Benjamin Netanyahu and a member of Mossad, the country's intelligence service, for 22 years prior to that.

"I thought that he, at the same time, took the high moral ground as well as the perceptive strategic view of the matter. This is my humble reaction to the leader of a great nation," Arad told The Canadian Press Thursday.

Arad offered the assessment after a hardline speech to hundreds attending a military symposium in Ottawa in which he advocated threatening Iran with attack as a way to force a diplomatic solution that would end its nuclear ambitions.

He highlighted Harper's recent remarks in the speech.

"The prime minister of Canada has similarly echoed that objective and provided an explanation to it: his fear that should Iran ever come into possessing nuclear weapons, the propensity for use, in the context of crisis or anything else, is so much greater than has been before with any other adversary, because of the combination of fanaticism and militancy that the Iranian regime has been characterized by."

Arad said that Netanyahu has also "noted the genocidal attributes of some of the declarations coming from the leaders of Iran when they refer to Israel."

Netanyahu in Ottawa next Friday

Harper hosts Netanyahu in Ottawa next week, a little more than a month after Foreign Affairs Minister John Baird visited Israel and said that it had no greater friend than Canada.

Iran denies it is trying to harness the technology needed to build a nuclear weapon, and says it is simply pursuing a peaceful energy program. The West, Canada included, doesn't believe that.

There is mounting speculation over whether Israel would launch a preemptive attack on Iran to disable its nuclear facilities -- an act that many analysts say would cause catastrophic geopolitical fallout.

But Arad argued that a nuclear-armed Iran would cause "ominous" changes to the Middle East, including a proliferation of nuclear weapons by other countries in the volatile region.

Arad stressed that he was no longer in the Israeli government, and that his views were his own.

John Noble, a retired veteran diplomat, who served as a Canadian ambassador to Greece and Switzerland, challenged Arad sharply after his speech.

"I'm in the minority view, which you outlined, that we could live with a nuclear Iran," Noble told Arad in front of hundreds of seated onlookers at the Conference of Defence Associations annual meeting.

"If I were worried about proliferation, if I were worried about a bomb I would worry more about the bomb the Pakistanis have, and the lack of control. That's a country which is a failed state," Noble added.

"What happens to Pakistan and India when they have the bomb? Suddenly they decide they can't use it. Your country has had a bomb for a long time. It has never used it."

Arad did not address Noble's assertion about Israel's nuclear capability, a topic the Jewish state does not publicly discuss.

'Credible' military threat suggested

Arad said he agreed with some of what Noble was saying. He reiterated the message of his speech: that Iran can be forced "under duress" to agree to a diplomatic solution that would see it abandon nuclear energy.

But Arad said that could not happen unless the international community delivers a clear military ultimatum to Iran to comply with United Nations resolutions calling for it to stop its nuclear enrichment programs or face an attack.

"War need not be the inevitable outcome if statesmanship and resolution is practised."

He said a deal is possible that would bring a "non-violent end" to the standoff with Iran but not without a show of force.

"The best use of the military threat is not to get there. And the only way not to get there is by making it credible," he said.

That includes directly threatening Iran's oil exports, but Arad didn't specify how.

Arad said any military attack on Iran would be a "surgical business" far less complicated than the attempts at regime change and democracy building in Afghanistan and Iraq.

"That is a job that can be done efficiently and effectively with no collateral damage," he said.

Defence Minister Peter MacKay and Gen. Walt Natynczyk, the chief of the defence staff, are to address the conference on Friday.