US Military Did Not Use Most Powerful Bunker-Buster Bombs on Iran's Isfahan Nuclear Site

Strategic Insights -

According to a closed-door briefing to lawmakers, the US military chose not to deploy its Massive Ordnance Penetrator (MOP) bunker-buster bombs against Iran's highly fortified Isfahan nuclear site during last weekend's strikes. This decision was made due to the site's depth, which would have rendered the MOP ineffective. Instead, Tomahawk cruise missiles were used to strike the site, which is believed to store nearly 60% of Iran's enriched uranium stockpile. The US military's strategy was to avoid causing significant damage to the underground structures, as it would have been difficult to destroy the sensitive materials stored within.

Key Takeaways:

  • The Massive Ordnance Penetrator (MOP) bunker-buster bomb, weighing 30,000 pounds, was not used at the Isfahan site due to its inability to reliably destroy the underground structures.
  • Tomahawk cruise missiles were used instead to strike the site, which is located in central Iran and considered one of Tehran's most strategically sensitive nuclear facilities.
  • The Isfahan site is believed to store nearly 60% of Iran's enriched uranium stockpile, with Highly Enriched Uranium (HEU) being the most critical nuclear material.
  • The US military's operation against the Fordow and Natanz nuclear sites resulted in moderate to severe damage to above-ground facilities.
  • The DIA's preliminary report confirms that Iran's core nuclear infrastructure, including enriched uranium, survived the attack and the program was likely set back by several months.
  • Senator Chris Murphy stated that some of Iran's capabilities are so far underground that the US military cannot reach them, allowing Iran to move sensitive materials into areas inaccessible to American forces.
  • President Donald Trump claimed that "nothing was moved" from the sites before the attack, despite lawmakers echoing concerns that the operation may not have destroyed the entire enriched uranium stockpile.

Statistics:

  • 30,000 pounds: The weight of the Massive Ordnance Penetrator (MOP) bunker-buster bomb.
  • 60%: The proportion of Iran's enriched uranium stockpile believed to be stored at the Isfahan site.
  • 900 pounds: The amount of Highly Enriched Uranium (HEU) that Senator Lindsey Graham said he does not know the current location of.
  • June 27: The date that Iranian access to the Isfahan tunnels reportedly resumed, according to satellite imagery from Planet Labs.

Sources:

  • "US General Tells Lawmakers US Military Did Not Deploy Bunker Buster Bombs on Isfahan Nuclear Site". CNN.
  • "DIA's Preliminary Report: Moderate to Severe Damage to Above-Ground Facilities at Three Nuclear Sites". Defense Intelligence Agency (DIA).
  • "Senator Chris Murphy on Iran's Nuclear Program: 'If They Still Have Enriched Material, Centrifuges, and the Capability to Reassemble Them into Cascades, We've Only Delayed Them by Months — Not Years'". CNN.
  • "Jeffrey Lewis on Iran's Nuclear Program: 'If Iran's Stockpile of HEU Was Still in the Tunnel When It Was Sealed, It May Be Elsewhere Now'". CNN.