For the better part of the past decade it was one of the most consequential questions in international affairs, with an answer that could potentially spark a war between two Middle Eastern military powers.
Just how close was Israel to attacking Iran's nuclear program? And if Israel ever launched a preventative strike on Iran's nuclear facilities, what would such an operation actually look like?
A blockbuster report by the Wall Street Journal's Adam Entous provides one possible answer. According to Entous, Israel planned a daring — and, in the US' view, disastrous and even suicidal — commando raid on Iran's Fordow nuclear facility in the early 2010s. Fordow ishome to 2,700 uranium enrichment centrifuges and is housed inside a hollowed-out mountain on an Iranian Revolutionary Guard Corps base.
"Cargo planes would land in Iran with Israeli commandos on board who would 'blow the doors, and go in through the porch entrance' of Fordow, a senior US official said," according to Entous. "The Israelis planned to sabotage the nuclear facility from inside."
At some point in 2011 or 2012, Israel was apparently serious enough about this plan to violate Iranian airspace in the course of its preparations: "Nerves frayed at the White House after senior officials learned Israeli aircraft had flown in and out of Iran in what some believed was a dry run for a commando raid on the site," Entous reported.
The "dry run" could have been doubly aimed at signaling the seriousness of Israeli intentions — and Israeli military capabilities — to a US administration that was then in the process of opening backchannel nuclear negotiations with Tehran. But the US took the possibility of an Israeli strike seriously enough to alter its defense posture in the Persian Gulf in response to a possible Israeli attack, sending a second aircraft carrier to region for some unspecified period of time, the Journal reported.
Until the Iran nuclear deal was signed this past July, an Israeli strike on Iran was one of the most intriguing — and perhaps terrifying — hypothetical scenarios in global politics. Israeli officials often argued the country was capable of launching an attack that would destroy or severely disable many of Iran's facilities. At times, Israel pointedly demonstrated its long-range strike capabilities. In October of 2012, Israeli jets destroyed an Iranian-linked weapons facility in Khartoum, Sudan, a city almost exactly as far from Israel's borders as Iran's primary nuclear facilities.
A September 2010 Atlantic Magazine cover story by Jeffrey Goldberg laid out what were believed to be the requirements of a successful Israeli attack on Iran's facilities. Israel has no strategic bombers; its fighters would have to use Saudi airspace in order to make it to Iran while maintaining enough of a fuel load to return to base. Some of its planes might have had to land in Saudi Arabia to refuel, or even use a temporary desert base as a staging area. (One of the intriguing unanswered questions in the Wall Street Journal story is whether Israeli planes crossed into Saudi airspace during the alleged "dry run.")
As Goldberg notes, it wouldn't be enough for Israel just to destroy Iranian facilities. The Israeli mission would also have to have a ground component to collect proof of a successful strike.
The consequences of a direct hit on Iran's facilities — something which might require the most sophisticated military operation in Israel's history — are unknowable ahead of time. Perhaps an attack would touch off a devastating escalation cycle in which Iranian linked terrorists attacked Israeli and US assets abroad, Iran launched attacks on Saudi targets to retaliate for their perceived cooperation, and the Iranian proxy militia Hezbollah unleashed its arsenal of 200,000 rockets at Israel.
Or maybe a jittery Tehran would hold back, cutting its losses after a superior military's direct hit on one of the regime's most important strategic assets. After all, neither Bashar al Assad nor Saddam Hussein retaliated when Israel destroyed their nuclear reactors from the air in2007 and 1981, respectively.
But administration of president Barack Obama was worried enough about the possible outcome of a strike to make the prevention of an Israeli attack one of it major foreign policy priorities. As Entous stresses, the US withheld information from Israel on the progress of its talks with Iran out of fear that Israel might attempt to sabotage the talks or use an attack to preempt a diplomatic resolution to the Iran issue.
Whether this was a legitimate fear was perhaps less important than the fact that the tactic worked: Israel hasn't attacked Iran yet, and the Iran Deal substantially raises the costs of a future strike for Israel. The deal signed this past July may or may not prevent Iran from developing a nuclear weapon. But it effectively removes an Israeli strike against the country from the realm of possibility into the foreseeable future.
As Entous's reporting indicates, it wasn't that long ago that Israeli officials really were thinking seriously about an Iran strike — enough to risk sending their planes into enemy territory, and raising tensions with their top ally.