in-cyprus 22 June 2025
The United States’ attacks on three Iranian nuclear facilities, with an emphasis on the underground Fordow complex, brought to the forefront of military technology the heaviest non-nuclear bombs in the Western arsenal: the GBU-57 Massive Ordnance Penetrator (MOP), also known as “Bunker Buster.”
What is the GBU-57 MOP?
The GBU-57 is specifically designed to strike deep underground facilities and fortified centers, such as the Fordow complex in Iran, which is buried up to 90 meters deep under a mountain. It is a GPS-guided bomb with a total weight of almost 13.6 metric tons (30,000 pounds), of which 2.4 metric tons (5,300 pounds) are explosive material.
The bomb’s body is made of a special high-strength steel alloy to maintain its structure during penetration into soil or concrete before detonating. It can penetrate up to 60 meters (200 feet) of concrete or rock before being detonated.
The explosion of the GBU-57 is estimated to have more than ten times the power of the older BLU-109, and it has the potential to cause devastating damage to underground nuclear facilities that were previously considered invulnerable.
Why Only the B-2 Can Carry It
Due to its enormous weight, the GBU-57 can be carried and released by only one aircraft worldwide: the American B-2 Spirit, a high-tech stealth strategic bomber.
The B-2 was designed to evade the most sophisticated anti-aircraft systems, with an aerodynamic design and the use of composite materials and special coatings that drastically reduce its thermal, radar, acoustic, and visual signature. Its low observability (stealth) makes it ideal for invading heavily protected airspaces.
The B-2 can carry two MOPs internally and fly 6,000 nautical miles without refuelling. The US attack on Iran, according to flight tracking experts, was carried out by B-2s that were refuelled mid-air by KC-135 Stratotankers, as they took off with a full load and limited fuel.
History and Prospects
The GBU-57s were developed by Boeing, and by 2015, only 20 had been manufactured. For years, members of Congress and defense analysts had suggested giving these bombs to Israel, but the idea was considered provocative and rejected, as only the B-2 can use them, and its technology remains strictly classified.
The US attack seems to confirm that the only country with the ability to strike at a depth of 90 meters is the United States and that the attempt to destroy Fordow could not have been undertaken without these bombs and the B-2s.
The Day After
The MOP attacks may mark a decisive turning point in the war, but also trigger chain reactions. The use of the most advanced US weapon systems indicates an intent for strategic escalation, even if – according to President Trump – there is no intention of regime change in Tehran.
As a US official tellingly stated to CBS, “the use of B-2s and MOPs is the strongest signal that could be sent.”
