Western spy agencies for years have kept watch on a craggy peak in northwest Iran that houses one of the world’s most unusual nuclear sites. Known as Fordow, the facility is built into mountain bunkers designed to withstand an aerial attack. Iran’s civil defense chief has declared the site “impregnable.”
But impregnable it is not, say U.S. military planners, who are increasingly confident about their ability to deliver a serious blow against Fordow should the president ever order an attack.
U.S. officials say they have no imminent plan to bombard the site, and they have cautioned that an American attack — or one by its closest Middle Eastern ally, Israel — risks devastating consequences such as soaring oil prices, Iranian retaliation and dramatically heightened tension in a fragile region.
Yet as a matter of physics, Fordow is far more vulnerable than generally portrayed, said current and former military and intelligence analysts. Massive new “bunker buster” munitions recently added to the U.S. arsenal would not necessarily have to penetrate the deepest bunkers to cause irreparable damage to infrastructure as well as highly sensitive nuclear equipment, probably setting back Iran’s program by years, officials said.
The weapons’ capabilities are likely to be a factor in discussions with a stream of Israeli leaders arriving in Washington over the next week. The Obama administration will seek to assure the visitors, including Defense Minister Ehud Barak and Prime Minister Benjamin Netanyahu, of U.S. resolve to stop Iran if it decides to build a nuclear bomb.
Israel has signaled in recent weeks that it may launch a preemptive strike against Iranian nuclear facilities, with little or no warning to its U.S. allies. The White House has urged Israel not to move hastily; making clear that the United States has the capacity to disrupt the Iranian program may give the Israelis reason to pause.
‘How many turns do you get?’
In arguing their case, U.S. officials acknowledged some uncertainty over whether even the Pentagon’s newest bunker-buster weapon — called the Massive Ordnance Penetrator — could pierce in a single blow the subterranean chambers where Iran is making enriched uranium. But they said a sustained U.S. attack over multiple days would probably render the plant unusable by collapsing tunnels and irreparably damaging both its highly sensitive centrifuge equipment and the miles of pipes, tubes and wires required to operate it.
“Hardened facilities require multiple sorties,” said a former senior intelligence official who has studied the formerly secret Fordow site and who agreed to discuss sensitive details of U.S. strike capabilities on the condition of anonymity. “The question is, how many turns do you get at the apple?”
U.S. confidence has been reinforced by training exercises in which bombers assaulted similar targets in deeply buried bunkers and mountain tunnels, the officials and experts said.
U.S. officials have raised the necessity of multiple strikes as they warn Israel against a unilateral attack on Iran’s nuclear installations, the officials said. While Israel is capable of launching its own bunker-buster bombs against Fordow, it lacks the United States’ more advanced munitions and the ability to wage a bombing campaign over days and weeks, American officials and analysts said.
The U.S.-Israeli rift over the urgency of stopping Iran’s nuclear progress stems in part from the belief among some Israeli officials that their window for successfully attacking Iran’s nuclear installations is rapidly closing as Tehran moves key assets into bunkers. Barak, in a speech this month, spoke of Iran’s progress in creating a “zone of immunity” for its nuclear program.
To U.S. military planners, a “zone of immunity,” if it exists at all, is years away. The Obama administration, while not ruling out a strike, regards military action as a last resort, preferring to allow more time for changing Iran’s behavior through economic and political pressure.
U.S. officials also remain unconvinced that Iran has decided to build a nuclear bomb, though they think it is pursuing the capacity to do so. Iran says its nuclear program is for peaceful energy production.
Under a mountain
Fordow is in the barren hills of northwestern Iran just outside Qom, an ancient city that is the spiritual home of the 1979 revolutionary movement. U.S. intelligence officials think tunneling began nearly a decade ago for what was intended to be a secret uranium-enrichment site that would operate parallel to the country’s much larger, declared enrichment plant at Natanz.
The CIA began monitoring the site at least four years ago, and in 2009, President Obama, flanked by other world leaders, publicly exposed the partially built facility and demanded that Tehran come clean about its intentions.