An Israeli strike won’t delay Iran’s nuclear weapons program. It will start it.

Last week, Joint Chiefs of Staff Chairman Gen. Martin Dempsey told reporters that an Israeli attack on Iran would “clearly delay but probably not destroy Iran’s nuclear program.” This is true enough, but it is important to note that the general did not say Iran’s nuclear weapons program.

While Iran’s ongoing nuclear enrichment program could be used to gather the material needed for a bomb, there is no definitive evidence that Iran has kicked off such a weaponization effort. The one thing that would almost surely launch an Iranian drive to weaponize, however, would be an Israeli strike.

While there is no clear indication Iran is currently working on a nuclear weapon, there is considerable evidence to the contrary. In fact, following the release of the 2011 National Intelligence Estimate on Iran, US Director of National Intelligence James Clapper confirmed in the spring of 2011 that he had a “high confidence” that Iran had not restarted their nuclear weapons program.

And International Atomic Energy Agency inspectors continue to meticulously monitor Iran’s stockpile of enriched uranium to make sure none is being diverted to any military related activities. Mohamed El-Baradei, the Nobel Peace Prize laureate who spent more than a decade as the director of the IAEA, said that he had not “seen a shred of evidence” that Iran was pursuing the bomb during his time at the agency (1997 – 2009), adding “All I see is the hype about the threat posed by Iran.”

Even Defense Secretary Leon Panetta acknowledged this fact: “Are [the Iranians] trying to develop a nuclear weapon? No. But we know that they’re trying to develop a nuclear [weapons] capability. And that’s what concerns us.”

Of course, a nuclear weapons capability comes with the territory: Any nation with a fully developed nuclear fuel cycle has such a weapons capability. In fact, this could be considered a major flaw in the Nuclear Non-proliferation Treaty. For instance, Japan, Argentina, and Brazil also have a latent nuclear weapons capability. Just like you can't get a speeding ticket for a car that is capable of going 110 miles per hour, it is not illicit to have a latent nuclear weapons capability.

An Israeli strike on Iran could change this latent capability into an active weaponization program. Iran’s response would likely include the expulsion of IAEA inspectors and a break-neck race to the bomb – not to mention the possibility of a region-wide conflagration and sky-high gas prices.

An Israeli strike would also have a “rally-around-the-flag” effect on the Iranian populace, allowing the regime to crack down further on political opponents and silence critics, cementing the regime’s authority.

Recent analysis shows that a previous Israeli strike – in 1981, on Iraq’s civilian Osirak nuclear reactor complex – led Saddam Hussein to demand a nuclear deterrent and was actually the trigger for Iraq launching a full-scale effort to weaponize. A decade later, by the time of the 1991 Gulf War, Iraq was on the verge of a nuclear weapons capability.

As researcher Malfrid Braut-Hegghammer explains in a recent International Security article, such ostensibly “preventive attacks can increase the long-term proliferation risk posed by the targeted state.”

Her research suggests that the conventional wisdom that Israel’s 1981 attack on Osirak denied Iraq a nuclear weapons capability no longer holds up: The strike actually created unprecedented pressure inside the Iraqi national security apparatus to pursue the bomb more vigorously than ever.

It is clear that senior echelons of the Israeli national security establishment understand this dynamic perfectly and are firmly against any strike on Iran.

For instance, former Mossad chief Efraim Halevy recently told Haaretz: “[W]hat I recommend is trying to calm the Iranian-Israeli conflict and not escalate it.”

He continues: “It is possible that, in the end, we will have no choice and will be forced to attack.....But before venturing on such an extreme and dangerous action, I suggest making a supreme effort to avoid it. We must not hem the Iranians in and we must not push them into a corner. We have to try to give them an honorable way out. It’s always worth remembering that the greatest victory in war is the victory that is achieved without firing a shot.”

It seems to be only some of Israel’s top political leaders who are calling for a strike. Commentators Nahum Barnea and Simon Shiffer wrote in Israel’s biggest-selling daily, Yedioth Ahronoth: “Insofar as it depends on Binyamin Netanyahu and Ehud Barak, an Israeli military strike on the nuclear facilities in Iran will take place in these coming autumn months, before the US elections in November.”

They later explain: “There is not a single senior official in the establishment – neither among the [Israeli Defense Forces] top brass nor in the security branches, or even the president – who supports an Israeli strike at the moment.”

So if an Israeli strike on Iran is such a transparently bad idea, why does Israeli Prime Minister Benjamin Netanyahu keep threatening one? Many – including Israeli politicians – speculate that this posturing is simply a cynical ploy to try to influence the outcome of the US elections by trying to paint Obama as weak on defense.

Former Israeli defense minister and current Kadima party leader Shaul Mofaz put it bluntly to Mr. Netanyahu, saying recently, “Mr. Prime Minister, you want a crude, rude, unprecedented, reckless, and risky intervention in the US elections. Tell us who you serve and for what? Why are you putting your hand deep into the ballot boxes of the American electorate?”

Quite apart from the fact that an Israeli attack on Iran would be against international law, it would likely convince Iran to kick out IAEA inspectors and kick off full-fledged nuclear weaponization.

As Ms. Braut-Hegghammer’s new analysis of the consequences of the 1981 Israeli strike on Iraq explains: “Such attacks may not only speed the targeted state’s efforts to produce nuclear weapons, but also create a false sense of security in the outside world.”

Yousaf Butt, a nuclear physicist, is professor and scientist-in-residence at the Monterey Institute of International Studies. The views expressed are his own.