The U.S. military did not deploy its most powerful bunker-buster bombs on Iran’s Isfahan nuclear facility due to its deep underground location, according to Joint Chiefs Chairman Gen. Dan Caine. The decision has raised questions about the actual impact of the U.S. airstrikes on Iran’s nuclear capabilities.

Isfahan Too Deep for Bunker-Busters

During a classified Senate briefing, Gen. Caine explained that the Massive Ordnance Penetrator (MOP) would not have effectively reached the deeply buried enrichment tunnels at Isfahan, which stores roughly 60% of Iran’s enriched uranium, according to U.S. assessments. Instead, the U.S. targeted Isfahan with Tomahawk cruise missiles launched from submarines.

Fordow and Natanz were both hit with more than a dozen bunker-buster bombs delivered by B-2 bombers.

Objective: Delay, Not Destroy

Despite Trump’s public claim that the nuclear program was “obliterated,” the Defense Intelligence Agency told lawmakers the strikes only set back Iran’s program by months, not years. GOP Rep. Greg Murphy confirmed, “To get rid of the nuclear material was not part of the mission.”

Democratic Sen. Chris Murphy warned that “Iran still has the know-how… and if they still have that enriched material, we’ve set the program back by months.”

Iran Clears Tunnels, Stockpile Remains a Mystery

Satellite imagery dated June 27 from Planet Labs shows Iranian vehicles clearing tunnel entrances at the Isfahan site. Jeffrey Lewis, a nuclear expert at the Middlebury Institute, said Iran could have relocated its uranium stockpile after sealing the tunnels during the strikes.

Lawmakers Demand Full Accounting

“There is enriched uranium in the facilities that moves around,” said Republican Rep. Michael McCaul. “We need a full accounting. That’s why Iran has to come to the table directly… so the IAEA can verify every ounce.”

Sen. Lindsey Graham added, “We don’t know where the 900 pounds of highly enriched uranium exists. But it wasn’t part of the targets there.”