27 June—The extent and effect of the damage actually inflicted on Iran’s nuclear capability by American bunker buster bombs may still be open to question, but the bombs themselves leave no doubt what they can do. And this is how they do it:

Bunker busters, formally designated Massive Ordnance Penetrators (MOPs), are specifically designed to penetrate incredibly deep into hard material like granite and concrete before detonating, thus maximizing their destructive power against so-called hardened and ordinarily impenetrable targets like underground facilities and (of course) bunkers.

The bunker busters accomplish the phenomenal feat through a combination of high mass (weight), super-hardened casing (shells), and ultra-sophisticated fuzing. (In common usage, while a fuse—with an s—is typically a simple burning cord or other device used to set off an explosion, a fuze—with a z—especially in military context, is a more complex mechanical and/or electronic device used to set off an explosive charge under specific conditions.)

Bunker busters, especially the bigger babies like the GBU-57s dropped on the Fordow uranium enrichment facility 250 to 300 feet under a mountain, whose specifics ar classified, are very very heavy. Think 30,000 pounds, with only—only?–5,000 pounds being explosives. The weight gives them the kinetic energy to smash through all the hard stuff. The GBU-57s are said to be able to penetrate 200 feet of reinforced concrete and rock but can probably do better. (In all events, imagine boring through 200 feet of concrete or granite. Evidently how long it takes a MOP is classified.)

The MOPs’ super-penetration is enhanced by casings made of super-hard alloys like Eglin steel or depleted uranium that allow the big bombs to withstand the impact of hitting hard surfaces without detonating prematurely. Shock absorbers probably are not used.

The super-fuzes in MOPs use computer technology and audio (and probably video) sensors to detect surrounding environment to delay detonation until programmed penetration into targeted spaces has been achieved. The explosive force is then aimed inward and downward in order to cause maximal structural damage and shockwaves.

The bunker-busting MOPs are dropped from exceptionally high (and currently classified) altitudes, allowing them to build up speed and kinetic energy to further enhance penetration and obliterate the bad guys.

At the moment, we’re told that only American B-2 bombers are equipped to deliver two 15-ton bunker busters apiece . . .