The United States military opted against using bunker-buster bombs on a major Iranian nuclear site. The primary reason, as explained by a top general to senators, was the site's extreme depth, which would have rendered the powerful Massive Ordnance Penetrator bombs ineffective.
This explanation by Gen. Dan Caine, Chairman of the Joint Chiefs of Staff, is the first known public disclosure regarding the decision not to deploy these specific munitions against the Isfahan facility in central Iran.
US officials suspect Isfahan's subterranean structures conceal a significant portion – nearly 60% – of Iran's enriched uranium, crucial for nuclear weapon production.
An early Defense Intelligence Agency assessment indicated that recent US strikes did not destroy the core components of Iran's nuclear program, including enriched uranium, likely only setting it back by months. There's also speculation Iran might have relocated some enriched uranium prior to the attacks.
While some Republican lawmakers acknowledged the strikes might not have eliminated all nuclear materials, they emphasized that this was not the military's objective. The mission focused on obliterating specific program aspects.
Despite significant damage to the sites, Iran retains the nuclear know-how. The setback is measured in months, not years, as concerns remain about their enriched material and centrifuge capabilities.
Source: https://saharareporters.com/2025/06/28/top-general-says-us-didnt-use-bunker-buster-bombs-irans-nuclear-sites-cites-depth