Editing Nuclear bunker buster (section)

== Policy and criticism of fallout ==
The main criticisms of nuclear bunker busters regard fallout and nuclear proliferation. The purpose of an earth-penetrating nuclear bunker buster is to reduce the required yield needed to ensure the destruction of the target by coupling the explosion to the ground, yielding a shock wave similar to an earthquake. For example, the United States retired the [[B53 nuclear bomb|B-53 warhead]], with a yield of nine [[TNT equivalent|megatons]], because the [[B61 nuclear bomb|B-61 Mod 11]] could attack similar targets with much lower yield (400 [[kiloton]]s),{{Citation needed|date=September 2007}} due to the latter's superior ground penetration. By burying itself into the ground before detonation, a much higher proportion of the explosion energy is transferred to [[seismic shock]]<ref>{{Cite journal |last=Nelson |first=Robert W. |date=January–February 2001 |title=Low-Yield Earth-Penetrating Nuclear Weapons |url=https://www.fas.org/faspir/2001/v54n1/weapons.htm |url-status=dead |journal=The Journal of the Federation of American Scientists |publisher=[[Federation of American Scientists]] |volume=54 |issue=1 |archive-url=https://web.archive.org/web/20060107023338/https://www.fas.org/faspir/2001/v54n1/weapons.htm |archive-date=7 January 2006}}</ref> when compared to the [[surface burst]] produced from the B-53's [[laydown delivery]]. Moreover, the globally dispersed fallout of an underground B-61 Mod 11 would likely be less than that of a [[surface burst]] B-53. Supporters note that this is one of the reasons nuclear bunker busters should be developed. Critics claim that developing new nuclear weapons sends a proliferating message to non-nuclear powers, undermining non-proliferation efforts.{{who|date=October 2020}}

Critics also worry that the existence of lower-yield nuclear weapons for relatively limited tactical purposes will lower the threshold for their actual use, thus blurring the sharp line between conventional weapons intended for use and weapons of mass destruction intended only for hypothetical deterrence, and increasing the risk of escalation to higher-yield nuclear weapons.<ref>{{Citation |url=http://www.hsfk.de/index.php?id=9&no_cache=1&detail=3124&no_cache=0&cHash=0991198fec |title=Intervention und Kernwaffen – Zur neuen Nukleardoktrin der USA |access-date=2008-02-15 |place=[[Germany|DE]] |first=Stephanie Sonius|last=Harald Müller |year=2006 |language=de |archive-url=https://web.archive.org/web/20110719042934/http://www.hsfk.de/index.php?id=9&no_cache=1&detail=3124&no_cache=0&cHash=0991198fec |archive-date=2011-07-19 |url-status=live}}</ref>

Local fallout from any nuclear detonation is increased with proximity to the ground. While a megaton-class yield [[surface burst]] will inevitably throw up many tons of (newly) radioactive debris, which falls back to the earth as fallout, critics contend that despite their relatively minuscule explosive yield, nuclear bunker busters create more local fallout per kiloton yield.{{citation needed|date=May 2014}} Also, because of the subsurface detonation, radioactive debris may contaminate the local groundwater.

The [[Union of Concerned Scientists]] advocacy group points out that at the [[Nevada Test Site]], the depth required to contain fallout from an average-yield [[underground nuclear test]] was over {{convert|100|m|ft|order=flip|sigfig=1}}, depending upon the weapon's yield. They contend that it is improbable that penetrators could be made to burrow so deeply. With yields between 0.3 and 340 kilotons, they argue, it is unlikely the blast would be completely contained.

Critics further state that the testing of new nuclear weapons would be prohibited by the proposed [[Comprehensive Test Ban Treaty]]. Although Congress refused to ratify the CTBT in 1999, and therefore this treaty has no legal force in the US, the US has adhered to the spirit of the treaty by maintaining a moratorium on nuclear testing since 1992.<ref>{{Citation |title=Comprehensive Nuclear Test Ban Treaty (CTBT) |publisher=MIIS |url=http://cns.miis.edu/inventory/pdfs/ctbt.pdf |date=10 May 2012 |archive-url=https://web.archive.org/web/20111025003946/http://cns.miis.edu/inventory/pdfs/ctbt.pdf |archive-date=2011-10-25 |url-status=live}}</ref>

Proponents, however, contend that lower explosive yield devices and subsurface bursts would produce little to no climatic effects in the event of a nuclear war, in contrast to multi-megaton air and surface bursts (that is, if the [[nuclear winter]] hypothesis proves accurate). [[air burst|Lower fuzing heights]], which would result from partially buried warheads, would limit or completely obstruct the range of the burning [[Effects of nuclear explosions|thermal rays]] of a nuclear detonation, therefore limiting the target, and its surroundings, to a fire hazard by reducing the range of thermal radiation with fuzing for subsurface bursts.<ref>{{Cite book |last1=Solomon |first1=Fredric |url=https://books.google.com/books?id=NUUrAAAAYAAJ&dq=radioactive+fallout+particles+surface+volume&pg=PA106 |title=The Medical Implications of Nuclear War |last2=Marston |first2=Robert Q. |date=1986-01-01 |publisher=National Academies Press |isbn=978-0-309-03692-4 |language=en}}</ref><ref name=":0">{{Cite book |last=Badash |first=Lawrence |url=https://www.worldcat.org/title/246200101 |title=A nuclear winter's tale: science and politics in the 1980s |date=2009 |publisher=MIT Press |isbn=978-0-262-01272-0 |series=Transformations : studies in the history of science (p. [317]-388) and technology |location=Cambridge, MA |oclc=246200101}}</ref>{{Rp|page=235}} Professors Altfeld and Cimbala have suggested that belief in the possibility of nuclear winter has actually made nuclear war more likely, contrary to the views of [[Carl Sagan]] and others, because it has inspired the development of more accurate, and lower explosive yield, nuclear weapons.<ref name=":0" />{{Rp|page=242}}