In this generalized climate of voltage caused by the flareweight of the Iran-Israel Wara lively debate has arisen, both among analysts and between the general public, regarding a very rare and particular weapon call “Gbu-57a/B Mop”. The reason for this unusual attention lies in the fact that it is considered by many experts as the only weapon capable of destroying the armored underground nucleus which different Iranian nuclear sites such as those of Fordow.
What is the GBU-57 Mop anti-Bunker bomb released by the USA in Iran
There GBU-57A/B MOP (acronym that is for “Guided Bomb Unit Number 57a/B Massive Ordnance Penetrator” in English) is, as the name itself says, one Guided bomb with very high penetrating capacity developed by United States of America To be released against particularly important targets and located within protected structures (and therefore defined “Antibunker bomb”). The studies that led to the birth of this powerful device already began in the aftermath of the War of Iraq of 2003but it was only in 2011 (after a long series of tests) that the bomb was accepted on duty, going to support the previous ones Gbu-28 And Gbu-37 In the Arsenale available to the Strategic Bombardieri Stealth Northrop B-2 Spirit.
Although it is formally a weapon with still classified characteristics, it is possible to realize the characteristics and performance of the GBU-57a/B Mop by studying its photos and analyzing the publicity on the subject. Overall, the bomb is 6.2 meters long and weighs almost 14 tons of which over four and a half are made up of explosive to very high potential (a mixture of AFX-757 And Pbxn-114 Optimized for a detonation in restricted spaces). The body of the bomb is enclosed in one EGLIN steel capsule (ES-1)the latter developed specifically to resist the extreme stresses of a deep penetration within the soil or other materials (some sources speak of depth up to 60 meters) before detonating.
Even if in the experimental phase, it was thought to make the GBU-57a/B Mop unloaded from the entire fleet of US strategic bombers (B-52, B-1B and B-2), and the first launch tests took place from a specimen of B-52 specially modified. In the end the bomb was produced only in modest quantities (the sources speak of just about twenty specimens) and opted only for its integration on B-2which can carry it 2 specimens each. However, the new American strategic bomber has already been announced Northrop Groumman B-21 Raider which will go alongside and gradually replace the triad of bombers today in service will also be equipped with the ability to transport and unhook the GBU-57a/B Mop.
Because the GBU-57 Top was used against nuclear bunkers in Iran
Since the Iran -Israel war broke out, in the Night between 12 and 13 June 2025the Israeli aerospace forces (IASF) repeatedly attacked all Iranian nuclear sites located within the envelope of theirs Standoff weapons. Although the damage imposed have been consistent, many aforementioned sites, in particular that of Fordow, are equipped with sections dug in the ground or even between the rocks precisely to make it impossible, or at least very difficult, complete destruction.
In the absence, until now, of signals about a possible use by Israeli of the nuclear weapons and not having the IDF (Israeli Defense Forces – Israeli Defense Forces) conventional weapons with penetrating capacity so performing, the leadership of the Jewish state He has repeatedly asked for an entrance to war at his side of the United States of America, specifically requesting that the Americans bombed the Fordow plant by means of their GBU-57a/b Mop.
Although at this moment the United States are engaged in a vast reunification of air assets in the Middle Eastern area, it is not clear whether the president Donald Trump has actually made the decision to enter the war, but if this scenario is to materialize, then the Iran-Israel war could become the stage for the “Baptism of fire” of the Gbu-57a/B Mop.
Anti-Bunker bombs are not a new concept
The operational concept of the “antibunker bombs” is not a novelty at all, and indeed it dates back to Second World War When all the belligerent nations inted to the creation of increasingly large and performing bombs to be used against particularly “hardened” objectives such as bunkers belonging to special strategic complexes (for example the basics of German submarines U-Boot located along the French coast). Among the many “antibunker bombs” that were lined up during the war, those that undoubtedly became the most famous were the “Tallboy”the “Grand Slam” and the “Disney Bomb”all of British design and production.
The development continued even after the conclusion of the war and led to the introduction to the United States of America of the ASM-A-1 TARZONthen used in the Korea war. Unlike the bombs of the Second World War, the Tarzon was equipped with a form, however primitive, of remote driving therefore it was more precise than its “older sisters” who, being bombs with free fall, had to be used in important numbers and relatively low altitudes to have the concrete probability of making a full center on the goal.
In subsequent conflicts, in every corner of the globe, all the weights have felt compelled to develop weapons of this type, coupled with more precise and refined driving systems, so much so that today they are considered in all respects indispensable weapons and widespread whose impact can potentially be devastating if used to obtain the destruction of high strategic objectives.
