Building activity rises at Iran nuclear mountain site as US eyes new bunker busters

The tail risk of a major escalation remains alive as attention returns to Pickaxe Mountain, since any strike on such a large site would surpass the tanker and infrastructure attacks that have boosted oil prices lately. Because the site is built into granite and current US bunker busting weapons may not be able to destroy it, a strike is not expected soon, which should restrain near-term market reaction. However, the Pentagon's development of a next-generation penetrator weapon, along with a mysterious emergency test program, indicates that a decisive action against the site remains a medium-term possibility, likely keeping a geopolitical premium in oil prices. Separately, unverified online speculation has raised the possibility of a US tactical nuclear option against the site. But CNN's reporting only covers conventional, non-nuclear weapons development, so that speculation is unconfirmed chatter, not a credible scenario.

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• WSJ: Trump aides privately caution that the Iran war could last his entire presidency

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Iran continues to excavate deeper at its most fortified suspected nuclear site, while satellite data indicates the US is quietly exploring ways to access it.

Summary:

• CNN reports that satellite imagery analysis by CSIS shows a surge in construction this year at Pickaxe Mountain, a suspected Iranian nuclear complex near Natanz thought to be fortified against attacks
• Analysts at CSIS assess that the facility is probably designed for centrifuge assembly, uranium enrichment, or as a refuge for other nuclear-weapons-related activities. They note that recent work has turned to internal construction and strengthening of tunnel entrances
• Because it is built into granite, the site poses a challenge even for the Pentagon's most powerful non-nuclear bombs currently in service. CNN adds that it is not the only Iranian nuclear site thought to be beyond the capability of existing munitions
• CNN connects a February emergency contract for a "unique subterranean test facility" at White Sands Missile Range in New Mexico, granted just before the war started, to US attempts to develop a method of striking Iran's deepest bunkers
• Trump has repeatedly warned of striking Pickaxe Mountain, and a source told CNN that the site was included in a target package being considered this summer. However, it is still unclear if current US weapons can penetrate deep enough to destroy any material Iran may have relocated there
• CSIS warns that even with the construction activity, the site does not yet seem ready for enrichment operations, should that be its purpose

A suspected Iranian nuclear facility, constructed deep under a granite mountain, experienced a notable rise in construction activity this year, per CNN, which references a previously unpublished satellite image analysis by the Center for Strategic and International Studies. The location, called Pickaxe Mountain, is near the Natanz nuclear complex south of Tehran and has for a long time been considered by intelligence agencies as a probable site for Iran to protect its nuclear program from additional attacks.

Analysts from CSIS informed CNN that the facility is probably intended for one of three roles in Iran's nuclear activities: centrifuge assembly, uranium enrichment, or a general refuge for weapons-related work like uranium metal conversion. The report notes that this year, the work has moved from active digging to internal building and fortifying tunnel openings, as well as paving internal roads and more vehicle movement at the site.

The mountain's granite makeup makes it a hard target for current US weapons, including the heaviest non-nuclear bombs in the arsenal. CNN says it is not the only Iranian nuclear site thought to be out of reach of existing munitions. Nevertheless, there are indications that the Pentagon is developing new methods to hit such facilities. CNN ties a February contract for emergency repairs on a subterranean test facility at White Sands Missile Range in New Mexico, signed just before the Iran war began, to a larger effort to create a next-generation bunker-busting weapon to replace the Massive Ordnance Penetrator. Satellite images reviewed by CNN indicate excavation and testing at the New Mexico site from February through March, but CNN could not independently verify whether a test occurred or its exact goal.

President Trump has frequently stated that the US could hit Pickaxe Mountain, and a source told CNN that the site was part of a target package being considered earlier this year. According to that source, it is still uncertain whether current US weapons can penetrate far enough to destroy whatever Iran may have moved there. CSIS analysts caution that, in spite of the substantial construction, the site still does not seem ready for enrichment work, if that is its final purpose, indicating that a decision on whether and how to strike it is still pending.