Washington, D.C. – August 1, 2025:
In a classified Senate briefing held Thursday, Chairman of the Joint Chiefs of Staff Gen. Dan Caine revealed that the United States military deliberately chose not to deploy bunker-buster bombs on Iran’s deeply buried Isfahan nuclear site during recent targeted strikes. The reason: the site’s depth exceeds the operational reach of even the most powerful American bunker-penetrating munitions.
This marks the first official clarification regarding the exclusion of the Massive Ordnance Penetrator (MOP) from the strike package aimed at the Isfahan facility, despite its known importance in Iran’s nuclear infrastructure. US intelligence assesses that Isfahan holds nearly 60% of Iran’s enriched uranium stockpile—a critical component in the potential development of a nuclear weapon.
Main Points of the Briefing:
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B2 bombers targeted Iran’s Fordow and Natanz nuclear sites with more than a dozen bunker-buster bombs.
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Isfahan was not hit with bunker-busters but instead struck by Tomahawk cruise missiles launched from a US Navy submarine.
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Gen. Dan Caine explained the decision stemmed from the extreme underground depth of the Isfahan facility.
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CIA Director John Ratcliffe confirmed that Isfahan and Fordow hold the majority of Iran’s enriched nuclear materials.
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Senator Chris Murphy noted that some Iranian nuclear capabilities are now so deep underground that even the most advanced US munitions can’t reach them.
Why It Matters:
The decision underscores the growing limitations of conventional military force against hardened nuclear infrastructure and raises critical questions about future US deterrence capabilities. According to military officials, while the Fordow and Natanz facilities were effectively targeted using bunker-busters, Isfahan’s deeper location necessitated a different tactical approach that prioritized missile strikes over deep-penetration bombing.
In the same briefing, Secretary of Defense Pete Hegseth and Secretary of State Marco Rubio participated alongside Gen. Caine and CIA Director Ratcliffe. The classified nature of the meeting restricted further public disclosures, but insiders confirmed that the threat posed by deeply buried Iranian facilities is now considered a top-tier strategic challenge.
When asked by reporters about the lack of bunker-buster deployment on Isfahan, a spokesperson for Gen. Caine declined to comment, citing the classified nature of the session.
Expert Analysis:
Military analysts suggest that Isfahan’s structural depth could be well beyond 200 feet underground, possibly protected by advanced concrete reinforcement, making even the 30,000-pound MOPs ineffective. This forces US military planners to consider alternative strategies such as cyber operations, regional alliances, or covert sabotage.
Senator Murphy’s Warning:
After the briefing, Democratic Senator Chris Murphy told CNN, “Some of Iran’s capabilities are so far underground that we can never reach them. So they have the ability to move a lot of what has been saved into areas where there’s no American bombing capacity that can reach it.”
This acknowledgment highlights a dangerous nuclear security loophole, reinforcing the importance of non-military options, surveillance, and diplomacy.
Conclusion:
The US military’s decision not to use bunker-buster bombs on Isfahan marks a strategic recalibration in dealing with hardened underground targets. It also sheds light on Iran’s ability to protect its nuclear assets by placing them beyond the reach of traditional airpower. As tensions continue, the Pentagon’s approach to future operations in the region may evolve—balancing firepower, intelligence, and diplomacy in the face of evolving nuclear threats.