U.S. Central Command has struck hardened Iranian anti-ship missile sites near the Strait of Hormuz, reportedly deploying heavy bunker-buster munitions against reinforced underground positions. Early reports suggest the possible use of the massive 5,000-pound GBU-72 Advanced Burster Bomb — the newest and most powerful conventional penetrator in the U.S. Air Force’s inventory. The strikes targeted fortified Iranian coastal defence positions from which anti-ship cruise missiles could threaten commercial and military shipping through one of the world’s most critical chokepoints.

Punching Through Concrete

The footage released alongside early reports shows the devastating impact of what appears to be a 2,000-pound BLU-109 penetrator — the warhead inside the GBU-24 Paveway III and GBU-31 JDAM — punching through reinforced concrete before detonating inside a hardened structure. The BLU-109 is designed to penetrate up to 1.8 metres of steel-reinforced concrete, and the resulting detonation collapses the structure from within. But the BLU-109 may have been merely the opening act. The GBU-72 Advanced Burster Bomb, which entered the USAF inventory recently, is a 5,000-pound class weapon specifically designed for deeply buried and hardened targets that smaller penetrators cannot reach. It fills the gap between the 2,000-pound GBU-31 and the 30,000-pound GBU-57 Massive Ordnance Penetrator — the bunker buster designed to threaten Iran’s deepest nuclear facilities.

Why the Strait Matters

The Strait of Hormuz is barely 33 kilometres wide at its narrowest point. Approximately 21 percent of the world’s petroleum passes through it daily. Iran has spent decades fortifying the coastline along both sides of the strait with anti-ship cruise missiles, fast attack craft bases, and coastal defence batteries. These positions are specifically designed to threaten shipping in the event of a conflict — and many are built into hardened bunkers carved into the mountainous terrain along the Iranian coast. Neutralising these sites has been a central planning objective for CENTCOM for years. The bunker-buster strikes represent a direct degradation of Iran’s ability to close or threaten the strait — a capability that Tehran has repeatedly vowed to exercise if attacked.

The Bunker Buster Evolution

The development of precision-guided penetrating weapons has been one of the quiet revolutions in modern airpower. During the 1991 Gulf War, Coalition forces discovered that many of Saddam Hussein’s command bunkers were impervious to conventional bombs. The urgent development of the GBU-28 — a 5,000-pound penetrator fabricated from surplus 8-inch artillery gun barrels and rushed to the theater in weeks — marked the beginning of a new class of weapons. Since then, the United States has developed an entire family of penetrators: the BLU-109 for standard hardened targets, the BLU-116 with enhanced penetration, the GBU-72 for deeply buried facilities, and the GBU-57 Massive Ordnance Penetrator for the most extreme targets. Each weapon represents a step deeper underground — a direct response to adversaries burying their most valuable assets further beneath rock and concrete.

Sources: Aviation Diary HD (Instagram), CENTCOM, USAF