Former Green Beret Lt. Col. Anthony Aguilar has raised questions about whether the U.S. military’s most powerful conventional bunker-buster could reach Iran’s deeply buried nuclear-linked facilities at Pickaxe Mountain near Natanz. In his analysis, Aguilar argues that the GBU-57 Massive Ordnance Penetrator (MOP), designed to strike hardened and deeply buried targets, may be unable to penetrate the mountain’s extensive rock and underground defenses, regardless of how many bombs are deployed. “No matter how many we drop, it can’t penetrate the Natanz facility,” Aguilar said, as diagrams illustrated the challenge facing weapons designed to destroy fortified installations. The GBU-57 weighs approximately 30,000 pounds and was developed specifically to attack heavily protected underground targets. However, Pickaxe Mountain is believed to house a tunnel complex buried roughly 80 to 100 meters beneath the surface, although the precise depth and internal layout remain uncertain. The facility’s location beneath a mountain presents a substantially different challenge from striking conventional underground bunkers beneath less substantial layers of earth and concrete.

Aguilar’s assessment highlights a central problem in military planning: a weapon’s ability to penetrate hardened material does not guarantee that it can reach or destroy every facility buried deep underground. The MOP was engineered to penetrate fortified structures, but its effectiveness against Pickaxe Mountain would depend on factors including the mountain’s geology, the depth and design of the tunnels, and the location of the intended targets. Independent analysts have also described the site as a particularly difficult target, noting that even the heaviest conventional U.S. munitions may struggle to destroy the underground complex completely. Satellite imagery assessments published in September and October 2026 indicate that access tunnels remain blocked and that the facility appears inactive, although analysts believe it may contain valuable equipment or materials. These uncertainties complicate assessments of what an airstrike could accomplish and whether damage to entrances or supporting infrastructure would achieve the intended military objective. The debate underscores the limits of conventional air power against deeply buried nuclear-related infrastructure and the strategic challenges facing Washington as it weighs options for addressing Iran’s nuclear program.