Mother of All Bombs Iran: Can the US Lawfully Hit Energy Sites?
Introduction
On October 14, 2026, CNN reported that the United States was considering using the “mother of all bombs” against Iranian energy infrastructure and nuclear facilities if President Donald Trump authorized renewed military operations. Officially designated the GBU-43/B Massive Ordnance Air Blast (MOAB), the weapon is a powerful conventional bomb designed to produce extensive blast effects. No decision to deploy it against Iran has been publicly announced, and Reuters was unable to independently confirm the reported military plans (Cohen, Britzky and Liptak, 2026; Reuters, 2026).
First used in combat against an Islamic State-Khorasan (ISIS-K) tunnel complex in Afghanistan in April 2017, the MOAB is primarily designed to deliver a massive explosive blast rather than penetrate deeply fortified structures (US Central Command, 2017). Although capable of damaging tunnels and relatively shallow underground positions, its effectiveness against Iran's heavily protected nuclear facilities remains uncertain. Its potential use against energy infrastructure also raises concerns about civilian casualties and damage to installations supplying electricity, fuel, and essential services.
International law does not categorically prohibit the MOAB, but the legality of the weapon does not establish the lawfulness of a particular strike. Any renewed American use of force against Iran must have a legal basis consistent with the United Nations Charter, while individual attacks remain subject to international humanitarian law. These are separate legal requirements: compliance with the rules governing the conduct of hostilities cannot independently justify an otherwise unlawful resort to force (United Nations, 1945).
Iranian energy infrastructure ordinarily enjoys protection as civilian property, although particular installations may qualify as military objectives. Under the customary rule reflected in Article 52(2) of Additional Protocol I, an object must make an effective contribution to military action by its nature, location, purpose, or use, and its destruction or neutralization must offer a definite military advantage in the circumstances prevailing at the time. Neither the United States nor Iran has ratified Additional Protocol I, making the customary status of the relevant targeting rules particularly significant (Additional Protocol I, 1977; ICRC, 2005).
Even when an energy installation qualifies as a military objective, an attack is prohibited if the expected incidental civilian harm would be excessive in relation to the concrete and direct military advantage anticipated. Feasible precautions must also be taken to minimize civilian harm, including reasonably foreseeable indirect consequences such as disruptions to electricity, water supplies, and medical services. Given the MOAB's extensive blast effects, the legality of any proposed strike would depend on the military function of the specific target, the anticipated consequences for civilians, and the justification for using force against Iran.
1. Why the Mother of All Bombs Is Being Considered for Iran
The possible deployment of the GBU-43/B against Iran has emerged from American military planning rather than an announced decision to resume large-scale bombing.
On October 14, 2026, CNN reported that US military planners had prepared additional strike options involving Iranian energy infrastructure and nuclear facilities. Some reportedly included the mother of all bombs, although officials questioned whether the weapon could achieve the desired military results (Cohen, Britzky and Liptak, 2026).
The proposals follow months of hostilities that began with US and Israeli strikes on Iran on February 28, 2026, under Operation Epic Fury. Subsequent fighting and diplomatic efforts have not produced a comprehensive settlement. The possibility of further attacks has consequently remained part of Washington's military planning, even after the reduction of major American combat operations.
Two distinct objectives emerge from the reported discussions. Further strikes might be intended to damage Iranian military capabilities, particularly facilities associated with energy supplies and nuclear activities. They could also serve a political purpose by increasing pressure on Tehran or allowing President Donald Trump to present a decisive conclusion to the confrontation. The legal significance of these objectives depends on whether particular attacks would achieve a recognized military advantage rather than merely produce economic damage or political pressure.
1.1 Trump's Reported Strike Options
CNN reported that Trump had requested additional military options involving substantial portions of Iranian energy infrastructure. One official familiar with the discussions described plans that included possible use of the MOAB, while another referred to underground nuclear facilities, including the installation known as Pickaxe Mountain. Reuters repeated the account on October 15 but stated that it could not independently confirm the reported plans (Reuters, 2026).
The existence of such options does not establish that the president has authorized their execution. Military planning encompasses alternative targets, weapons, and operational scenarios, some of which may never be adopted. The White House declined to discuss the reported plans, while the Pentagon provided a general explanation of its responsibility to prepare for different operational requirements (Cohen, Britzky and Liptak, 2026).
The political context complicates the strategic calculation. CNN described discussions within the administration about securing an outcome that could be presented as a conclusion to the conflict. Some officials reportedly doubted that further bombing would compel Iran to accept American demands. An operation selected principally for its psychological or political effects would still require a lawful target and compliance with the restrictions governing military force.
1.2 The Military Value of Energy and Underground Targets
Energy installations can contribute to military operations by supplying electricity, fuel, and industrial resources. Air bases, naval facilities, weapons production, and military communications may depend on infrastructure that also serves the civilian economy. Disrupting a facility's contribution to military action could produce a tangible operational advantage, although the extent of that advantage would depend on its particular function.
The relationship becomes less direct where the intended effect is economic. Refineries and oil terminals may generate government revenue without supplying particular military operations. Electricity networks may support military establishments while simultaneously serving hospitals, water systems, and residential areas. These differences are central to determining whether an installation qualifies as a military objective and what civilian consequences an attack might cause.
Underground nuclear facilities present a separate problem of military effectiveness. CNN identified Pickaxe Mountain among the potential targets under discussion, but publicly available information does not conclusively establish the activities conducted within the installation. Officials familiar with the planning questioned whether the MOAB could penetrate its suspected geological protection. A weapon capable of causing extensive surface destruction might fail to disable equipment situated deep underground, reducing the military advantage expected from its use.
2. The GBU-43/B: Capabilities and Military Limitations
The GBU-43/B Massive Ordnance Air Blast is a GPS-guided conventional explosive weapon developed by the US Air Force Research Laboratory at Eglin Air Force Base, Florida. Weighing approximately 21,600 pounds, it was developed rapidly before the 2003 invasion of Iraq and underwent testing in March of that year. Its design emphasizes an exceptionally powerful explosive blast rather than the penetration of deeply fortified structures (US Air Force, 2008).
The MOAB is not a nuclear weapon. Its destructive effects result from conventional explosives, while satellite guidance allows it to be delivered toward a designated location. Accurate delivery does not confine the resulting explosion to that location. The weapon's large blast effects distinguish it from smaller precision-guided munitions whose destructive effects may be more geographically limited.
The United States first employed the MOAB in combat on April 13, 2017, against an Islamic State-Khorasan tunnel complex in Afghanistan's Nangarhar province. US Central Command described the operation as an effort to destroy fortified positions and reduce risks to American and Afghan forces conducting operations nearby (US Central Command, 2017). That deployment demonstrated its use against a tunnel network, but it does not establish that the weapon would be effective against Iran's deeply hardened nuclear installations or appropriate for use near civilian energy infrastructure.
2.1 MOAB Versus the GBU-57 Massive Ordnance Penetrator
The GBU-43/B differs substantially from the GBU-57 Massive Ordnance Penetrator, a heavier conventional weapon developed specifically for hardened and deeply buried targets. The GBU-57 weighs approximately 30,000 pounds and is designed to penetrate protective material before detonating. By contrast, the MOAB relies primarily on extensive blast effects, making the two weapons suitable for different military purposes (US Air Force, 2019).
The distinction became relevant during Operation Midnight Hammer in June 2025, when American B-2 bombers employed GBU-57 weapons against Iranian nuclear facilities, including Fordow. The Department of Defense confirmed the use of these penetrators and subsequently reported that they had functioned as designed. American claims concerning the operation's success must nevertheless be distinguished from independently established findings about the lasting condition of the targeted facilities (US Department of Defense, 2025).
Greater explosive effects do not necessarily produce greater penetration. A deeply buried installation may be protected by rock formations, reinforced structures, or substantial distances between the surface and essential equipment. The anticipated effectiveness of a weapon depends on those characteristics rather than its explosive weight alone. This also affects the legal assessment: foreseeable civilian harm cannot be evaluated independently of the military result that planners reasonably expect the attack to achieve.
3. The Legal Basis for Renewed US Military Operations
Article 2(4) of the United Nations Charter establishes the general prohibition on the threat or use of force against another state. Article 51 preserves the inherent right of individual or collective self-defense if an armed attack occurs, while the Security Council may authorize military enforcement measures under Chapter VII. Self-defense is also governed by customary requirements of necessity and proportionality, which limit the force used to address the relevant armed attack (United Nations, 1945).
The United States has expressly defended Operation Epic Fury as an exercise of self-defense. In a March 10, 2026 letter to the Security Council, recorded as S/2026/161, Washington invoked Article 51 in connection with the military operations launched on February 28. On April 21, State Department Legal Adviser Reed Rubinstein provided a fuller justification, arguing that the operations formed part of an ongoing international armed conflict and were undertaken in both American self-defense and collective defense of Israel (United States, 2026; Rubinstein, 2026).
That position remains contested. The American argument relies partly on earlier Iranian attacks and the proposition that hostilities constitute a continuing armed conflict rather than a succession of unrelated confrontations. Critics, including former State Department lawyer Brian Finucane, have challenged whether the factual circumstances establish the armed attacks required for self-defense and whether earlier hostilities can justify renewed military action without a sufficient present connection to defensive necessity (Finucane, 2026).
The existence of an international armed conflict is relevant to the application of international humanitarian law, but it does not independently establish a continuing right to use force under the Charter. A further American operation would require a valid justification in the circumstances prevailing when force was employed. The necessity and proportionality of self-defense must also be distinguished from proportionality in attack, which concerns incidental civilian harm in relation to anticipated military advantage.
3.1 The ICJ's Oil Platforms Judgment
The International Court of Justice examined an earlier confrontation involving American attacks on Iranian energy infrastructure in Oil Platforms (Islamic Republic of Iran v. United States of America). Its November 6, 2003 judgment concerned US naval attacks against Iranian offshore oil installations in October 1987 and April 1988. Washington maintained that the operations responded to attacks affecting American vessels and interests in the Persian Gulf (ICJ, 2003).
The proceedings arose under the 1955 Treaty of Amity between Iran and the United States. The Court considered whether the attacks could be justified under Article XX(1)(d), which concerned measures necessary to protect essential security interests. In interpreting that provision, the Court examined the rules governing self-defense, including the existence of an armed attack and the requirements of necessity and proportionality.
The Court found that the United States had not established the conditions necessary to justify its attacks on the platforms as acts of self-defense. It also questioned the evidence concerning their asserted military significance. The operations consequently could not be justified under the treaty's essential-security exception. The Court's reasoning addressed fundamental rules on the use of force, although its jurisdiction remained based on the particular treaty dispute (ICJ, 2003).
Iran nevertheless failed on its separate claim concerning freedom of commerce under Article X(1). The Court concluded that the attacks had not been shown to interfere with commerce between the territories of the two states in the manner protected by that provision. Oil Platforms did not establish a general prohibition on attacking oil infrastructure. Its relevance to the proposed MOAB strikes lies principally in the need to demonstrate a legally sufficient defensive justification rather than relying on the strategic importance attributed to energy installations.
4. Can Iranian Energy Infrastructure Be a Military Objective?
International humanitarian law ordinarily protects energy infrastructure as civilian property. Electricity stations, refineries, pipelines, and export terminals are not lawful military targets simply because they form part of a state's economy. Their status depends on whether they satisfy the legal definition of a military objective in the circumstances of the proposed attack.
Some installations may perform functions directly connected to military operations. A fuel facility supplying combat aircraft or a power station serving military command systems could contribute effectively to military action. Other facilities may primarily support civilian activities, even when their operation indirectly benefits the state conducting the war.
The distinction becomes particularly difficult with interconnected energy networks. An installation may simultaneously provide essential civilian services and support military establishments. Its potential military status does not eliminate the obligation to assess the effects of disabling civilian functions. Nor does the military use of one part of a network automatically justify attacking every facility within it.
4.1 Additional Protocol I Article 52 and Customary IHL
Article 52(2) of Additional Protocol I defines military objectives through two cumulative requirements. An object must make an effective contribution to military action by its nature, location, purpose, or use, and its destruction, capture, or neutralization must offer a definite military advantage in the circumstances prevailing at the time. Article 52(1) establishes the corresponding protection of civilian objects against attack (Additional Protocol I, 1977).
The definition requires more than evidence that an installation is economically important or belongs to the government. Its contribution must concern military action, and the expected advantage must be sufficiently definite. The classification may change as the object's purpose or use changes, but an attacker cannot rely on an unsupported assumption of military activity.
Article 52(3) establishes a presumption concerning objects normally dedicated to civilian purposes when doubt exists about their use in making an effective contribution to military action. The customary status and precise application of that treaty provision have generated disagreement. The US Department of Defense nevertheless revised its Law of War Manual in July 2023 to recognize a legal duty to presume persons and objects protected from attack unless available information indicates that they are military objectives. Commanders must exercise good-faith military judgment and take feasible precautions to verify proposed targets (US Department of Defense, 2023).
4.2 Power Stations, Refineries, and Dual-Use Facilities
A fuel depot supplying Iranian military operations may qualify as a military objective if disabling it would produce a definite military advantage. A refinery presents a more complicated assessment because its products may serve military and civilian consumers through the same distribution network. Evidence of actual or intended military use is relevant, but the legal classification cannot rest solely on the refinery's importance to national fuel production.
Electricity generation creates similar difficulties. A power station may supply military communications, weapons manufacturing, hospitals, residential neighborhoods, and water treatment facilities. Even where its military contribution satisfies the targeting requirements, the foreseeable disruption of civilian services remains relevant to proportionality and feasible precautions.
The ICRC has specifically addressed this problem in its March 2026 guidance concerning the Middle East. It rejects the sweeping classification of an entire electricity grid or energy network as a military objective merely because some facilities support military operations. The Department of Defense also recognizes the obligation to assess individual objects using available information, although the United States adopts a broader interpretation of certain economically significant military objectives (ICRC, 2026; US Department of Defense, 2023).
4.3 Economic Warfare and the War-Sustaining Debate
The status of infrastructure that generates revenue for military expenditure is more contested than that of facilities supplying weapons, fuel, or operational services. Iranian oil exports contribute to government income, but government revenue finances civilian activities alongside military expenditure. Whether an installation's economic contribution alone can establish its military character depends partly on competing interpretations of the military-objective definition.
The United States has adopted a relatively broad interpretation encompassing certain war-sustaining capabilities. Its Law of War Manual recognizes economic objects that contribute to an adversary's ability to sustain military operations as potential military objectives. This approach permits consideration of economic support beyond the immediate supply of resources to armed forces (US Department of Defense, 2023).
The ICRC rejects treating general economic contributions as sufficient. Its interpretation requires an effective contribution to military action rather than the broader capacity to finance or sustain a war. In its 2026 guidance, the organization specifically opposed attacks on energy infrastructure undertaken solely to diminish economic capacity, influence the civilian population, or pressure political leaders into negotiations (ICRC, 2026).
These interpretations cannot be presented as a single uncontested rule. A terminal supplying fuel to military operations presents a different legal question from an export facility selected primarily to reduce Iranian revenue. Under the ICRC's interpretation, economic pressure alone would not establish a lawful military objective; the broader American approach remains disputed. Neither position removes the requirements governing proportionality, precautions, and the prohibition of indiscriminate attacks.
5. The MOAB Under the Rules of International Humanitarian Law
The GBU-43/B is not categorically prohibited under international humanitarian law merely because it produces extensive conventional explosive effects. The legality of a weapon as such must be distinguished from the legality of its use in a particular attack. Even a weapon capable of accurate delivery may cause unlawful harm if directed against civilians or employed in circumstances where its effects cannot be sufficiently limited.
The MOAB's large blast area is particularly relevant to the selection of targets near populated locations. An explosion capable of damaging a substantial area may affect civilian buildings and infrastructure beyond the intended military objective. The legal assessment must account for the expected physical effects of the chosen weapon, rather than relying exclusively on the accuracy of its guidance system.
These considerations differ according to the target's surroundings. A military position in an isolated area presents different risks from an energy installation surrounded by workers, residential buildings, and essential services. Distinction, proportionality, and precautions apply in both circumstances, but the foreseeable civilian consequences may vary considerably.
5.1 Proportionality and Civilian Harm
The customary rule of proportionality prohibits attacks expected to cause incidental civilian deaths, injuries, or damage to civilian objects that would be excessive in relation to the concrete and direct military advantage anticipated. Article 51(5)(b) of Additional Protocol I expresses this prohibition. It applies even when an object has been correctly classified as a military objective (Additional Protocol I, 1977; ICRC, 2005).
The anticipated advantage must be assessed in relation to the relevant military attack. State practice recognizes that an attack may need to be considered as a whole rather than through an artificial division into isolated components. This does not permit the expected advantage to be expanded indefinitely to include the political objectives of an entire war or speculative benefits from damaging a national economy (ICRC, 2005).
For a MOAB strike against energy infrastructure, the assessment would include the expected blast effects and reasonably foreseeable consequences beyond the immediate installation. Disabling electricity generation may interrupt hospital equipment, water pumping, sewage treatment, and communications systems. Where such effects are reasonably foreseeable, they must be considered alongside direct civilian casualties and physical destruction (ICRC, 2026).
Proportionality does not establish a fixed numerical exchange between civilian losses and military advantage. The assessment depends on information reasonably available to those planning or deciding the attack. Uncertainty about a weapon's ability to achieve its intended military purpose is relevant because the anticipated advantage must rest on a reasonable assessment of likely results. An attack expected to produce extensive civilian harm for a doubtful military benefit would require particularly close scrutiny.
5.2 Indiscriminate Attacks and Feasible Precautions
International humanitarian law prohibits indiscriminate attacks, including operations not directed at a specific military objective and attacks employing means or methods whose effects cannot be limited as required by law. These prohibitions are reflected in Article 51(4) of Additional Protocol I and customary international humanitarian law (ICRC, 2005).
The MOAB's GPS guidance allows it to be delivered toward a selected location, but precision of delivery does not guarantee discrimination in its destructive effects. An accurately delivered bomb may still affect civilian objects over an extensive area. Conversely, its explosive power does not make every conceivable use indiscriminate. The decisive considerations include the target's location, the expected blast effects, and whether the attack can distinguish sufficiently between military objectives and protected persons or objects.
Feasible precautions require the verification of proposed targets and appropriate consideration of civilian risks. Article 57 of Additional Protocol I sets out detailed precautionary obligations, many of which reflect customary law. These include selecting feasible means and methods that avoid or minimize incidental civilian harm, providing effective advance warnings when circumstances permit, and canceling or suspending an attack when its unlawfulness becomes apparent.
The choice of weapon is part of that assessment. Planners may need to consider available alternatives, different points or times of attack, and the likely effectiveness of each option. Feasibility takes account of relevant humanitarian and military considerations rather than imposing an absolute requirement to select the least destructive weapon in every circumstance. A commander cannot, however, disregard a practicable precaution simply because a powerful weapon has been selected.
5.3 Military Pressure and the Prohibition of Civilian Terror
The MOAB's psychological effects have been associated with its military purpose since its development. Its exceptionally powerful explosion can intimidate opposing forces and demonstrate destructive capability. CNN reported that some officials considered psychological impact a possible reason for deploying the weapon against Iran, particularly where its effectiveness against hardened underground facilities was uncertain (Cohen, Britzky and Liptak, 2026).
Psychological pressure against opposing armed forces is not automatically unlawful. International humanitarian law nevertheless prohibits acts or threats of violence whose primary purpose is to spread terror among civilians. Article 51(2) of Additional Protocol I expresses this rule, which is also recognized as customary law (ICRC, 2005).
The prohibited purpose cannot be inferred merely because civilians would experience fear following an attack. The relevant distinction concerns the intended purpose of the violence and its relationship to lawful military operations. The available reporting does not establish an intention to terrorize Iranian civilians. Still, using an explosion principally to intimidate civilian populations would raise a separate legal problem, and psychological pressure cannot substitute for the requirement to attack a lawful military objective.
6. Nuclear Facilities and Environmental Consequences
Attacks against nuclear facilities and major energy installations may produce consequences beyond the immediate destruction of equipment. Nuclear sites can contain materials whose release would create serious hazards, while refineries and fuel storage facilities may contain large quantities of flammable or toxic substances. The risks depend on the facility's characteristics, the materials present, and the expected effects of the attack.
These consequences are relevant even when the installation qualifies as a military objective. Damage to containment systems, fires, contamination, and interruption of essential services may cause civilian harm extending beyond the initial blast area. Their foreseeable effects must be considered under the rules of proportionality and precautions.
Certain installations also benefit from special legal protections. Additional Protocol I establishes heightened protection for specified works containing dangerous forces and includes provisions concerning damage to the natural environment. The applicability of those treaty provisions to a US-Iran conflict cannot be assumed, making it necessary to distinguish their terms from corresponding customary obligations.
6.1 Article 56 and the Protection of Nuclear Installations
Article 56 of Additional Protocol I establishes special protection for dams, dikes, and nuclear electrical generating stations. Under its first paragraph, these installations must not be attacked, even when they qualify as military objectives, if the attack may release dangerous forces and cause severe civilian losses. The protection also extends to certain nearby military objectives where attacking them could produce those consequences (Additional Protocol I, 1977).
This protection is conditional rather than absolute. Under Article 56(2)(b), the special protection of a nuclear electrical generating station may cease if it supplies electricity in regular, significant, and direct support of military operations and an attack is the only feasible way to terminate that support. Comparable conditions govern certain military objectives at or near protected installations. Even when special protection ceases, the general rules protecting civilians continue to apply.
A nuclear electrical generating station must also be distinguished from an enrichment plant or another nuclear-related installation. Article 56 does not automatically extend its express treaty protection to every facility associated with nuclear technology. Such facilities remain protected as civilian objects unless they qualify as military objectives, and attacks must comply with all applicable rules governing civilian harm.
Neither Iran nor the United States is a party to Additional Protocol I. Its detailed Article 56 restrictions cannot consequently be imposed on them simply as treaty obligations. Customary international humanitarian law nevertheless requires particular care when attacks concern installations containing dangerous forces. The ICRC identifies this obligation in Rule 42 of its customary law study, while the precise relationship between customary protection and the Protocol's detailed conditions requires separate interpretation (ICRC, 2005).
6.2 Oil Fires, Pollution, and Environmental Protection
A major explosive attack on an oil refinery, fuel depot, or gas installation may produce fires, toxic emissions, and contamination of surrounding areas. The scale of the damage depends on the substances present, industrial containment measures, and the conditions of the attack. Smoke and hazardous releases may affect civilian communities located beyond the immediate area of destruction.
The natural environment receives protection under the ordinary rules governing attacks. Environmental objects that do not qualify as military objectives are protected against direct attack, while foreseeable incidental environmental damage is relevant to proportionality. Feasible precautions must also account for environmental consequences where they can reasonably be anticipated (ICRC, 2020).
Additional Protocol I provides heightened environmental protection through Articles 35(3) and 55. Article 35(3) prohibits means or methods of warfare intended or expected to cause widespread, long-term, and severe damage to the natural environment. Article 55 addresses such harm where it prejudices the health or survival of the population. The cumulative threshold requires all three characteristics, making these provisions distinct from ordinary rules concerning incidental environmental damage (Additional Protocol I, 1977).
The customary status of this heightened prohibition remains contested. The ICRC identifies a corresponding customary restriction in Rule 45, while the United States expressly challenged that characterization in its 2006 response to the ICRC's customary international humanitarian law study (Bellinger and Haynes, 2006; ICRC, 2005). This disagreement does not remove the general protections against unlawful environmental harm. An attack may breach distinction, proportionality, or precautions even where the expected environmental damage does not satisfy the heightened threshold.
7. Applying International Law to the Proposed Iran Strikes
The reported MOAB plans cannot be classified as lawful or unlawful without identifying the proposed targets and examining the circumstances of the attacks. CNN's reporting does not establish which particular Iranian energy installations would be selected or what military advantage American planners expect from destroying them. The legality of a strike would depend on those facts, the weapon's anticipated effects, and the legal justification for renewed force.
A military fuel depot directly supporting combat aircraft or other military operations could qualify as a military objective. If its destruction offered a definite military advantage, an attack might satisfy the targeting requirement. The operation would nevertheless have to meet proportionality and precautionary obligations. A MOAB strike producing extensive foreseeable civilian damage could be unlawful even if the depot itself were a legitimate target.
A dual-use electricity station presents a different assessment. Its supply of power to military installations might establish an effective contribution to military action, but disabling the station could also interrupt essential civilian services. The anticipated advantage would need to be assessed against foreseeable direct and indirect civilian harm. Available alternatives and the possibility of limiting disruption would be relevant to feasible precautions.
Oil export infrastructure presents the additional question of economic targeting. A terminal selected because it directly supplies military fuel operations could have a stronger military justification than one chosen primarily to reduce Iranian export revenue. The United States adopts a broader interpretation of war-sustaining economic objectives than the ICRC, but that disagreement cannot eliminate the need for a definite military advantage or justify indiscriminate and disproportionate attacks.
An underground nuclear facility would require a separate assessment of its actual military function and the likely effectiveness of the MOAB. Public reporting concerning Pickaxe Mountain does not establish the nature of all activities conducted there or the effects that the weapon would produce against its suspected protective structures. If the anticipated attack were unlikely to disable a qualifying military objective while exposing civilians or civilian infrastructure to substantial harm, the proposed operation would face serious proportionality and precautionary concerns.
All these scenarios remain subject to the law governing the use of force. Washington's assertion of continuing individual and collective self-defense must be evaluated under Article 51 of the United Nations Charter, including necessity and proportionality. A lawful military objective does not independently authorize an attack on another state. The reported plans establish possible military options, but they do not demonstrate that any particular operation would satisfy both the rules governing resort to force and those regulating the conduct of hostilities.
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Conclusion
The United States could lawfully employ the mother of all bombs against an Iranian energy installation only if the operation satisfied the applicable requirements governing the use of force and the conduct of hostilities. The GBU-43/B is not categorically prohibited, and energy infrastructure is not absolutely protected from military attack. Its military status must nevertheless be established through the contribution of the specific installation to military action and the definite advantage anticipated from attacking it.
A strike selected primarily to damage Iran's economy or compel political concessions would face substantial legal objections, particularly where the target lacks a sufficient military function. The broader American interpretation of war-sustaining economic objectives remains contested. Even where an installation qualifies as a military objective, the MOAB's extensive blast effects must be assessed against foreseeable civilian harm, the availability of feasible precautions, and any applicable special protections.
The October 2026 reports do not establish that a MOAB attack has been authorized or that any proposed target satisfies these requirements. The legal conclusion depends on the justification for renewed American force, the military character of the chosen installation, and the reasonably anticipated consequences of employing the weapon. Its destructive power cannot independently establish either military necessity or compliance with international humanitarian law.
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