[dabigv13]

Today Trump said he will decide in two weeks whether to join militarily. It seems he may have some concerns about whether US conventional bombs could destroy Fordow. I am not an engineer or physicist, but it does seem like even the strongest conventional weapons could have trouble with it- it's not like one leaves a big tunnel for the next one- there will be a crater but the rock and earth does not vaporize, subsequent bombs still need to get through that material. Maybe with enough bombs you can get deep enough but it would seem to me to be a matter of diminishing returns, and the US has a somewhat limited number of these weapons from what I have read. Possibly the shock waves could collapse the underground tunnels, but can you be certain?

Some reporting on this-

https://www.theguardian.com/world/2025/j...icials-say

Donald Trump has suggested to defense officials it would make sense for the US to launch strikes against Iran only if the so-called “bunker buster” bomb was guaranteed to destroy the critical uranium enrichment facility at Fordow, according to people familiar with the deliberations.

Trump was told that dropping the GBU-57s, a 13.6-tonne (30,000lb) bomb would effectively eliminate Fordow but he does not appear to be fully convinced, the people said, and has held off authorizing strikes as he also awaits the possibility that the threat of US involvement would lead Iran to talks.
.......
The effectiveness of GBU-57s has been a topic of deep contention at the Pentagon since the start of Trump’s term, according to two defense officials who were briefed that perhaps only a tactical nuclear weapon could be capable of destroying Fordow because of how deeply it is buried.

Trump is not considering using a tactical nuclear weapon on Fordow and the possibility was not briefed by defense secretary Pete Hegseth and the chairman of the joint chiefs of staff Gen Dan Caine in meetings in the White House situation room, two people familiar with the matter said.

But the defense officials who received the briefing were told that using conventional bombs, even as part of a wider strike package of several GBU-57s, would not penetrate deep enough underground and that it would only do enough damage to collapse tunnels and bury it under rubble.

Those in the briefing heard that completely destroying Fordow, which Israeli intelligence estimates to go down as far as 300ft (90 metres), would require the US to soften the ground with conventional bombs and then ultimately drop a tactical nuclear bomb from a B2 bomber to wipe out the entire facility, a scenario Trump is not considering.

The assessments were made by the Defense Threat Reduction Agency (DTRA), a component of the defense department that tested the GBU-57, as it reviewed the limitations of US military ordinance against a number of underground facilities.

An interesring thread on the above article, taking issue with the description of a "tactical nuclear weapon". The expected bomb to be used would likely be a B61 with a yield of 300-400 kt (compare to 15 and 21 for Hiroshima and Nagasaki). They only go 3m below ground before exploding, unlike the conventional MOP (est 60m), and thus there would be a lot fallout, similar to a ground level nuclear explosion.

I say this because people often wrongly refer to "low-yield bunker busters" that don't exist. EPWs are high-yield weapons that produce significant fallout capable of killing tens of thousands of people. References to "tactical" nuclear weapons may reinforce that misperception.

https://x.com/ArmsControlWonk/status/193...6191100181
https://www.nytimes.com/2025/06/19/opini...clear.html

Bombing Fordo — and whatever might come after — might not set back Iran’s enrichment efforts by nearly as long. There are hundreds or more likely thousands of scientists and technicians employed in Iran’s enrichment program. Israel’s killing of leading scientists is intended to set back this effort, but Iran could almost certainly reconstitute its program within 10 or 15 years, even if the United States and Israel succeeded in destroying Fordo and Iran’s stockpiles of enriched uranium and centrifuge components.

And military action is unlikely to be so definitive. Destroying Fordo is relatively easy compared with destroying the cylinders in which highly enriched uranium is typically stored. These cylinders are roughly the same size and shape as scuba tanks. Before the attack in Iran, most of them were thought to be stored underground at Isfahan, where they were regularly inspected. They may well survive attack, if they are still there. It is possible Iran has already moved them, in which case, tracking them will be exceptionally difficult.
.....
There is a clear double standard here. In the United States and particularly on Capitol Hill, diplomatic agreements are scrutinized. The weaknesses that inevitably result from compromise are highlighted, debated and assessed — and rightly so. But as America’s decisions to go to war in Vietnam, Afghanistan and Iraq attest, military options are routinely held to a much lower standard. That’s a very dangerous pattern, especially because serious questions about the effectiveness of a U.S. attack on Iran abound.

How long could it take Iran to reconstitute its program? If Iran rebuilds, is the United States prepared to attack again? And again? Given that Iran could hide new facilities or bury them more deeply than Fordo, would future attacks have any chance of success? Could a U.S. attack push Iran to make the political decision to build a nuclear weapon? If the Iranian regime collapses as a result of a U.S. attack — as some advocates of military action want — is there any guarantee that a new government will abandon the country’s long-held nuclear ambitions?

Diplomacy and military action deserve to be judged by the same standard. Neither can guarantee that Iran will never obtain the bomb. But even at this late stage, Iran has indicated a willingness to negotiate. Given its current weakness, Mr. Trump really might be able to secure a better deal than the previous one.

[dabigv13]

Today Trump said he will decide in two weeks whether to join militarily. It seems he may have some concerns about whether US conventional bombs could destroy Fordow. I am not an engineer or physicist, but it does seem like even the strongest conventional weapons could have trouble with it- it's not like one leaves a big tunnel for the next one- there will be a crater but the rock and earth does not vaporize, subsequent bombs still need to get through that material. Maybe with enough bombs you can get deep enough but it would seem to me to be a matter of diminishing returns, and the US has a somewhat limited number of these weapons from what I have read. Possibly the shock waves could collapse the underground tunnels, but can you be certain?

Some reporting on this-

https://www.theguardian.com/world/2025/j...icials-say

Donald Trump has suggested to defense officials it would make sense for the US to launch strikes against Iran only if the so-called “bunker buster” bomb was guaranteed to destroy the critical uranium enrichment facility at Fordow, according to people familiar with the deliberations.

Trump was told that dropping the GBU-57s, a 13.6-tonne (30,000lb) bomb would effectively eliminate Fordow but he does not appear to be fully convinced, the people said, and has held off authorizing strikes as he also awaits the possibility that the threat of US involvement would lead Iran to talks.
.......
The effectiveness of GBU-57s has been a topic of deep contention at the Pentagon since the start of Trump’s term, according to two defense officials who were briefed that perhaps only a tactical nuclear weapon could be capable of destroying Fordow because of how deeply it is buried.

Trump is not considering using a tactical nuclear weapon on Fordow and the possibility was not briefed by defense secretary Pete Hegseth and the chairman of the joint chiefs of staff Gen Dan Caine in meetings in the White House situation room, two people familiar with the matter said.

But the defense officials who received the briefing were told that using conventional bombs, even as part of a wider strike package of several GBU-57s, would not penetrate deep enough underground and that it would only do enough damage to collapse tunnels and bury it under rubble.

Those in the briefing heard that completely destroying Fordow, which Israeli intelligence estimates to go down as far as 300ft (90 metres), would require the US to soften the ground with conventional bombs and then ultimately drop a tactical nuclear bomb from a B2 bomber to wipe out the entire facility, a scenario Trump is not considering.

The assessments were made by the Defense Threat Reduction Agency (DTRA), a component of the defense department that tested the GBU-57, as it reviewed the limitations of US military ordinance against a number of underground facilities.

An interesring thread on the above article, taking issue with the description of a "tactical nuclear weapon". The expected bomb to be used would likely be a B61 with a yield of 300-400 kt (compare to 15 and 21 for Hiroshima and Nagasaki). They only go 3m below ground before exploding, unlike the conventional MOP (est 60m), and thus there would be a lot fallout, similar to a ground level nuclear explosion.

I say this because people often wrongly refer to "low-yield bunker busters" that don't exist. EPWs are high-yield weapons that produce significant fallout capable of killing tens of thousands of people. References to "tactical" nuclear weapons may reinforce that misperception.

https://x.com/ArmsControlWonk/status/193...6191100181
https://www.nytimes.com/2025/06/19/opini...clear.html

Bombing Fordo — and whatever might come after — might not set back Iran’s enrichment efforts by nearly as long. There are hundreds or more likely thousands of scientists and technicians employed in Iran’s enrichment program. Israel’s killing of leading scientists is intended to set back this effort, but Iran could almost certainly reconstitute its program within 10 or 15 years, even if the United States and Israel succeeded in destroying Fordo and Iran’s stockpiles of enriched uranium and centrifuge components.

And military action is unlikely to be so definitive. Destroying Fordo is relatively easy compared with destroying the cylinders in which highly enriched uranium is typically stored. These cylinders are roughly the same size and shape as scuba tanks. Before the attack in Iran, most of them were thought to be stored underground at Isfahan, where they were regularly inspected. They may well survive attack, if they are still there. It is possible Iran has already moved them, in which case, tracking them will be exceptionally difficult.
.....
There is a clear double standard here. In the United States and particularly on Capitol Hill, diplomatic agreements are scrutinized. The weaknesses that inevitably result from compromise are highlighted, debated and assessed — and rightly so. But as America’s decisions to go to war in Vietnam, Afghanistan and Iraq attest, military options are routinely held to a much lower standard. That’s a very dangerous pattern, especially because serious questions about the effectiveness of a U.S. attack on Iran abound.

How long could it take Iran to reconstitute its program? If Iran rebuilds, is the United States prepared to attack again? And again? Given that Iran could hide new facilities or bury them more deeply than Fordo, would future attacks have any chance of success? Could a U.S. attack push Iran to make the political decision to build a nuclear weapon? If the Iranian regime collapses as a result of a U.S. attack — as some advocates of military action want — is there any guarantee that a new government will abandon the country’s long-held nuclear ambitions?

Diplomacy and military action deserve to be judged by the same standard. Neither can guarantee that Iran will never obtain the bomb. But even at this late stage, Iran has indicated a willingness to negotiate. Given its current weakness, Mr. Trump really might be able to secure a better deal than the previous one.