On Sunday, President Donald Trump renewed his threat of massive attacks on Iran. Claiming “We’re offering a very fair and reasonable DEAL,” he warned that if they don’t take it, “the United States is going to knock out every single Power Plant, and every single Bridge, in Iran. NO MORE MR. NICE GUY! They’ll come down fast, they’ll come down easy….” In doing so, he doubled down on his earlier threats to target Iran’s infrastructure (possibly even desalination plants), thereby bombing Iran “back to the stone age,” and his warning that “a whole civilization will die tonight, never to be brought back again.”
The U.S. Ambassador to the United Nations, Michael Waltz, took to the Sunday morning political talk shows to defend the Trump administration’s actions and the President’s threats (NBC’s Meet the Press transcript, ABC’s This Week transcript, CBS’s Face the Nation transcript). In doing so, he offered the most detailed purported legal justifications for those threats to date. Indeed, he confirmed that he wanted to “get ahead of this other ridiculous and frankly irresponsible narrative that this would somehow constitute a, quote, ‘war crime,’ that we’ve heard from Democratic politicians, the media, and others in the international community.” On all three shows, he proactively raised the issue before the anchor did – an ominous sign that he may be laying the groundwork for the U.S. military to follow through on the President’s statements. Although a former Army Special Forces officer and former National Security Advisor, Waltz is neither a lawyer nor in the chain of command.
He is wrong on the law of war crimes, both because he misses the import of the international law rule he’s attempting to explain, and because the rule that he addresses is but one of many that limit attacks on infrastructure used by civilians. Waltz is also wrong for a more fundamental reason – it is beyond dispute that threats to destroy a whole civilization, or the infrastructure on which it depends for survival, are both criminal and deeply immoral. Attempting to lay a legal veneer over them is pernicious, anathema to the rule of law, and deeply damaging to the honor of the U.S. military at a time when it is engaged in the very armed conflict that forms the context for these threats.
In this piece, we assess Waltz’s assertions against the law of armed conflict (LOAC) rules that apply in an international armed conflict, including the current one between the United States and Iran (and other countries involved in the war). The United States bears responsibility for violations of those rules by the U.S. armed forces (LOAC violations are an “internationally wrongful act” under the law of State responsibility). In some cases, the operations in question will also qualify as war crimes or crimes against humanity by those involved, particularly when the attack is directed at civilian objects, is indiscriminate, or is clearly disproportionate.
We conclude that while there is a basis in law for some of Waltz’s claims, they are not only exaggerated but also fail to offer the full picture. Our analysis is limited to issues of targeting, although aspects of the interviews raised other legal questions, such as his statement that “it’s the U.S. Navy and President Trump that decide what comes in and out” of the Strait of Hormuz, a claim of authority exceeding what the law of naval warfare allows during blockades (see Mark Nevitt’s analysis of blockade law). In light of Waltz’s position as U.S. Ambassador, our assessment relies heavily on the law as outlined in the U.S. Department of Defense’s Law of War Manual..
Disentangling “Dual Use” of Civilian Infrastructure
During ABC’s This Week interview, Waltz stated that “attacking, destroying infrastructure that has clearly and historically been used for dual military purposes is not a war crime” and that it is “perfectly acceptable in the rules of land warfare” to target objects due to the enemy’s “commingling” military infrastructure with civilian sites. In a similar vein, on CBS’s Face the Nation, he asserted that “in the laws of land warfare and the rules of engagement, civil–any type of infrastructure that is being commingled, that is being used to move military hardware is absolutely a legitimate target.” That statement alone is only partly correct, and, more importantly, it is only one variable when determining whether an attack on a given target is lawful. Indeed, any law of armed conflict expert can recognize that the conspicuous absence of the rest of the equation, discussed below, proves Waltz wrong.
First, to qualify as a “military objective,” a term that refers to an object that may lawfully be attacked (subject to satisfaction of other LOAC rules like proportionality and precautions in attack), an object must “by its nature, location, purpose or use makes an effective contribution to military action;” and second, the object’s “total or partial destruction, capture or neutralization, in the circumstances ruling at the time,” must provide “a definite military advantage” (§ 5.6.3). This DoD Law of War Manual definition mirrors that appearing in Additional Protocol I, Article 52(2) for Parties (see also CCW Amended Mines Protocol, art. 2(6), and CCW Protocol III on Incendiary Weapons, art. 1(3); State Department Legal Adviser 2016 Remarks), and is understood as reflective of customary international law binding on all States.
Thus, the law imposes a two-part test (§ 5.6.5). The “use” (current use of an object) and “purpose” (the object’s intended future use) criteria are most relevant to the infrastructure at issue here. Waltz is correct that the military’s present or future use of civilian infrastructure may satisfy the first prong of the test, so long as that contribution is “effective.” This is a fairly low bar. To be effective, the object needs only to be “useful … to the armed forces” (ICRC Commentary, ¶ 2022). The second prong requires that an attack on the object yield a “definite military advantage.” The ICRC Commentary on the article explains that “it is not legitimate to launch an attack which only offers potential or indeterminate advantages.”
In most cases, an object that satisfies the first prong of the military objective test, such as a bridge that is presently used by the armed forces or a power plant that generates power on which the military relies, will satisfy the second. This is true even if it is also used for civilian purposes, and indeed even if civilian use predominates. As noted in the HPCR Manual on International Law Applicable to Air and Missile Warfare, “Any military use of a civilian object renders it a military objective. However, the fact that it has become a military objective by use does not exclude the possibility of simultaneous civilian use.” (p. 119).
To this point, Waltz is correct: so-called “dual-use” objects presumably qualify as military objectives. But there are limits. As we explain below, the full set of rules governing who and what may be targeted in armed conflict provides several key safeguards for the civilian population that effectively render some of these objects not lawfully targetable, despite qualifying as military objectives.
The Many Ways it is Unlawful to Destroy Categories of Targets
The key LOAC limitation on carrying out Trump’s threats is that each target must independently qualify as a military objective. It is over this requirement that Waltz tripped. During the ABC interview, Jonathan Karl asked whether the President was “prepared to do what he threatened here? He said destroy every power plant and every bridge in the country?” Waltz responded, “Well, all options are on the table, absolutely.”
Doing so would clearly be unlawful. Beyond military equipment, there are no “categories” of targets that universally qualify as military objectives. Accordingly, an attack on an entire category of infrastructure violates LOAC and most likely is a war crime by some of those involved, including those who ordered the strikes. This kind of attack would be unlawful on several grounds.
First, to attack an entire category of infrastructure knowing (or in circumstances where a reasonable attacker in the same or similar circumstances would know) that particular targets therein failed to qualify as a military objective violates the prohibition on directly attacking civilian objects. The law is clear: “Persons, objects, and locations that are not military objectives may not be made the object of attack” (DoD Law of War Manual, § 5.5.2).
Second, if the United States began destroying all targets in the category without attempting to distinguish among them, the strikes would qualify as indiscriminate attacks. As noted in the U.S. Navy/Marine Corps/Coast Guard Commander’s Handbook on the Law of Naval Operations, indiscriminate attacks, defined as “[a]ttacks that are not directed at a specific military objective,” are prohibited. (§ 5.3.4; see also practice associated with Customary IHL study, rule 11)
Third, because the purpose of such a broad operation is to destroy all components of a category of civilian infrastructure, even the otherwise rather low bar for considering a dual-use object may not have been met. After all, if the whole point is to destroy the infrastructure to force concessions in negotiations, rather than to achieve an operational military end, then it is at least questionable whether the attack makes an effective contribution to military action and offers a definite military advantage.
Fourth, destroying all targets within any given category of infrastructure used by civilians would almost certainly violate the rules on proportionality and precautions in attack, as we explain below.
Fifth, such an attack would almost certainly violate rules on depriving civilians of objects indispensable to their survival. Attacking every power plant, bridge, desalination facility, or other critical infrastructure would foreseeably deprive civilians of water, food, electricity necessary for medical care, or other essentials. This rule, found in Article 54(2) of Additional Protocol I, is considered customary by the ICRC, but not the United States. Nevertheless, the DoD Law of War Manual observes that “the United States has supported the underlying principle that starvation of civilians may not be used as a method of warfare” (§ 5.20.4).
And sixth, any threat to destroy an entire category of infrastructure used by civilians likely constitutes a LOAC violation and war crime of threatening violence aimed at terrorizing the civilian population. The rule is simple, and is recognized as binding customary international law applicable in all armed conflicts: “Measures of intimidation or terrorism against the civilian population are prohibited, including acts or threats of violence, the primary purpose of which is to spread terror among the civilian population” (DoD Law of War Manual, § 5.2.2). Thus, Trump’s threats of violence (as supported by Waltz and reiterated by Secretary Hegseth), if intended primarily to spread terror among civilians in Iran, are themselves LOAC violations and war crimes, even if not carried out.
On this score, it is unclear what Waltz intended when he replied, in response to a question about whether striking all of the targets would be a war crime, “if you go back in the history of warfare, go all the way back to World War II, of course we bombed and took down bridges, other infrastructure, power plants.” That’s not legal support; it’s an anachronism at best. The destruction of Dresden and firebombing of Tokyo to terrorize the civilian population is precisely what led to those methods of warfare being outlawed through Additional Protocol I to the Geneva Conventions (art. 51(2)) and customary international humanitarian law.
War-Sustaining Targets?
On Meet the Press, Waltz tried to justify targeting these objects on the ground that “power plants, the grid, and other things that are being used to power Iran’s war economy, which, oh, by the way, the IRGC controls an estimated 40% to 50% of.” At one level, it’s a remarkable admission by Waltz. What about the other 50-60% that the President and Secretary of Defense threatened to destroy? How could that be justified? Also, the military destruction of an enemy’s economy is the “total warfare” of World War II and earlier conflicts, long since outlawed by international law and moral dictates.
To put Waltz’s comments on their strongest potential legal footing, perhaps he meant to invoke the notion of targeting “war-sustaining” objects. We addressed that line of argument in our March Q&A:
A more controversial theory is that petroleum facilities may be targeted as so-called “war-sustaining” objects on the basis that they generate revenue that supports the enemy’s war effort. The DoD Law of War Manual asserts that “[e]conomic objects associated with military operations or with war-supporting or war-sustaining industries have been regarded as military objectives” (emphasis added). As examples, it points to “oil refining and distribution facilities, and objects associated with petroleum, oil, and lubricant products (including production, transportation, storage, and distribution facilities)” (§ 5.6.8.5). This approach is not universally accepted, and many States and commentators (including Mike and Tess) take the view that the law of armed conflict requires a more direct nexus to military action than a general economic contribution. Accordingly, while petroleum facilities may in some circumstances qualify as lawful targets—particularly where they directly support military operations—their targeting on a purely “war-sustaining” basis remains legally contested.
What’s more, as Lieutenant Colonel W. Casey Biggerstaff wrote, even on the view that war-sustaining objects can be targetable in some circumstances, that “does not displace the requirement that a military objective exhibit a discernable causal connection to enemy military action;” there is no rule that petroleum facilities per se may be targeted; and economic resources “do not qualify as military objectives merely because they contribute to the overall pool of resources available to its adversaries.”
In other words, even if the war-sustaining approach is valid as a matter of law, it would not support the types of attacks being suggested. And as for Waltz’s point that the “IRGC controls” a large percentage of the Iranian economy, we fail to see the legal significance. The IRGC may also control institutions of higher education or other purely civilian activities and facilities. It does not make those legitimate military targets.
Proportionality and Precautions in Attack
A central purpose of the law governing the conduct of hostilities is to spare the civilian population from the effects of war to the greatest extent possible (DoD Law of War Manual, § 5.2). To achieve this animating purpose, the fundamental rule of distinction provides that civilians and civilian objects may never be made the object of attack. This is a bright-line rule. Beyond this, a series of more nuanced LOAC rules limits attacks on targets even if they qualify as lawful military objectives. Most of those rules are codified in Additional Protocol I to the Geneva Conventions (to which the United States is not a party) and reflect customary international law (binding on all States); the United States accepts these rules as binding, in relevant part.
The rules of proportionality and precautions in attack are particularly important in limiting harm to the civilian population. As we explained in our March Q&A:
A key protection beyond the prohibition on directly attacking civilians and civilian objects is the rule of proportionality (see Q 9), which prohibits attacks in which the expected incidental loss of civilian life, injury to civilians, or damage to civilian objects would be excessive in relation to the concrete and direct military advantage anticipated from the attack (DoD Law of War Manual, § 5.12; Additional Protocol I, arts. 51 and 57).
As noted in the DoD Law of War Manual, “[d]etermining whether the expected incidental harm is excessive does not necessarily lend itself to quantitative analysis because the comparison is often between unlike quantities and values” (§ 4.23). Rather, it requires a good-faith, highly context-dependent judgment made before the attack as to whether the harm caused to civilians will be “excessive.” For instance, killing a high-value target such as a senior military leader will allow for greater incidental civilian injury or death or damage to civilian property than killing a low-level fighter. Moreover, the evaluation is made by those who plan, approve, and execute the attack and is based on the information reasonably available to them at the time.
Importantly, the question of what types of harms qualify as “incidental harm” that must be factored into a proportionality assessment is somewhat contested. However, incidental civilian deaths or injuries, and damage to civilian objects, must be included in the analysis. Speculative effects that are not reasonably foreseeable need not be included. Likewise, “[m]ere inconvenience or temporary disruptions to civilian life” need not be factored into the proportionality calculation (DoD Law of War Manual, § 5.12.1.2). That said, reasonably foreseeable effects are not speculative; they must be weighed in a proportionality analysis, and the commander must include such effects in a proportionality analysis even if they are “indirect.”
Plainly speaking, and as a practical matter, it is impossible for an attack on all critical infrastructure of any category to be proportionate; no order to commence such an operation could comply with the rule. For example, what is the concrete and direct military advantage of destroying the fifth power plant? The tenth? The last? How about the power plant located in a remote area with no significant military use? Moreover, it is implausible that the destruction of that last power plant would not result in excessive harm to civilians of the type factored into the proportionality calculation, given the incremental military advantage.
The rules on precautions in attack also limit the targeting of dual-use infrastructure in operationally significant ways. Again, as explained in the March Q&A:
Attackers must take all feasible measures to verify that targets are lawful military objectives and have to consider feasible alternatives—including different targets, timing, tactics, or weapons—that would achieve the desired military advantage while reducing the risk of civilian harm (DoD Law of War Manual, § 5.11; Additional Protocol I, art. 57). Additionally, attackers must effectively warn the civilian population if it will be affected by the attack. Doing so is required when the circumstances permit, as when surprise is not an element of the attack and the target is fixed (e.g., a building).
Although the United States does not accept the premise (DoD Law of War Manual, § 5.2.3.5), the ICRC and some experts assert that there is a customary law obligation for attackers to exercise “constant care” to “spare” civilians and civilian objects, a broad obligation that requires them to consider the impact of their operations on the civilian population. We agree.
In practical terms, an operation that aims to target and destroy all objects within any category (bridges, power plants, oil production facilities, desalination plants, or any other category of infrastructure used by civilians) cannot possibly comply with these requirements, long recognized by the United States as obligatory and fundamental.
To make this plain, consider the following: An order is given to begin destroying all bridges in Iran (or perhaps all bridges in a given region). What feasible alternatives were considered to destroying a particular bridge? None, if the goal of the operation is simply to destroy them all. Similarly, when it comes to power plants, Trump and Hegseth have both explicitly spoken about destroying all Iranian power plants. Why not instead neutralize or disable them temporarily, as U.S. munitions or cyber operations can do in many circumstances, and as the requirement to take feasible precautions may require?
Iranian LOAC Violations are Not an Excuse for U.S. LOAC Violations
Finally, we must dispense with a red herring. On ABC’s This Week, Waltz denied that the threatened attacks would be prohibited, pointing to Iranian violations of LOAC.
So, and the Iranian regime in particular and its terrorist proxies have a long history of actually deliberately hiding military infrastructure in hospitals, schools, neighborhoods, and other — and other civilian assets. So, they are standing on — they have no ground to stand on…. And … the Iranian regime is launching drones and missiles directly into civilian homes, hotels and resorts across the Gulf.
So, this is just a ridiculous argument we’ve heard in the media and from the Iranians and frankly, from some lawmakers here at home.
However, the law applies equally to both sides of a conflict, irrespective of their status as aggressor or victim under the law governing the resort to force (jus ad bellum). This “principle of equal application,” as it is known, also applies to all other situations, including when the enemy violates LOAC itself (as Iran has certainly done). Such violations do not relieve its adversary of the obligation to conduct hostilities lawfully. As an example, with respect to the protection of civilians, Article 51(8) of Additional Protocol I to the Geneva Conventions provides that “Any violation of [the prohibition on human shielding] shall not release the Parties to the conflict from their legal obligations with respect to the civilian population and civilians, including the obligation to take the precautionary measures provided for in Article 57.” And Article 60(7) of the Vienna Convention on the Law of Treaties states that the entitlement to suspend a treaty in the face of another Party’s material breach does not apply to “treaties of a humanitarian character, in particular to provisions prohibiting any form of reprisals against persons.”
Neither Iran nor the United States is a Party to Additional Protocol I, but the principle it reflects is undoubtedly customary law (DoD Law of War Manual, § 5.4.4). Citing the DoD’s 1992 Final Report on the Persian Gulf War, the DoD Manual confirms that “a nation confronted with callous actions by its opponent … is not released from its obligation to exercise reasonable precaution to minimize collateral injury to the civilian population or damage to civilian objects.”
The sole exception is the taking of belligerent reprisals, defined in the DoD Law of War Manual as “acts taken against a party: (1) that would otherwise be unlawful; (2) in order to persuade that party to cease violating the law” (§ 18.18.1). The legality of reprisals is a fraught LOAC issue (see Mike’s analysis here and here). For instance, Additional Protocol I prohibits reprisals to such a degree that threatened U.S. actions would clearly be unlawful (see compilation in DoD Law of War Manual, § 18. 18.3.4). The United States, however, only acknowledges limitations found in treaties to which it is Party, such as the CCW Amended Mines Protocol and 1949 Geneva Conventions, which do not encompass much of the infrastructure Trump is threatening to attack.
Nevertheless, a claim of reprisal would fail at the most fundamental level. As reflected in the Manual’s definition, the sole purpose of a reprisal is to “influence a party to cease committing violations at present and in the future” (§ 18.18.1.3). Here, both Trump and Waltz have made it crystal clear that the purpose is to coerce Iran into agreeing to U.S. demands for ending the conflict. But even if the purpose criterion was satisfied, “to be legal, reprisals must respond in a proportionate manner to the preceding illegal act by the party against which they are taken” (§ 18.18.2.4). Bombing the enemy into the “Stone Age” hardly satisfies that requirement. Nor is Waltz even speaking in the language or framework of reprisals; he is speaking in the terms of retribution for past Iranian acts, a language that is anathema to the laws of war, though it may play well for particular political audiences.
Concluding Thoughts
Waltz is right about one thing – under the laws governing the conduct of hostilities in war, civilian infrastructure does not enjoy categorical immunity merely because civilians use it. Bridges, power plants, communications facilities, transportation systems, fuel storage facilities, and other infrastructure may, in case-specific circumstances, qualify as targetable military objectives when they make an effective contribution to military action and attacking them offers a definite military advantage.
But that does not mean every dual-use object may lawfully be targeted — rules on proportionality and precautions, among others, must independently be met. In short, the fact that infrastructure is dual-use does not relieve attackers of the obligation to assess whether expected civilian harm would be excessive in relation to the anticipated military advantage, or to take feasible precautions to minimize harm to civilians and civilian objects. And it certainly does not mean entire categories of critical infrastructure may be treated as targetable. Attacks based on the presumption that every object within some broad category is a lawful target would, at a minimum, be indiscriminate and could amount to war crimes by those involved.
Iran’s own unlawful conduct does not alter this conclusion. Its many violations of the law of armed conflict are utterly objectionable, but the law applies equally to all parties, regardless of the enemy’s misconduct. And because the Trump administration has made clear that the purpose of prospective operations would be to compel Iran to accept U.S. terms for ending the conflict, even recharacterizing them as belligerent reprisals—a highly contentious basis for action in any event—could not justify the threatened attacks.
The question, at bottom, is whether U.S. officials will respect fundamental LOAC requirements or instead pretend that the law permits what it plainly forbids. On that question, Waltz’s statements should alarm anyone concerned with the rule of law, the protection of civilians, and the honor of the U.S. armed forces.
