striking

The U.S. military has been using M142 High Mobility Artillery Rocket Systems (HIMARS) to strike Iranian ships as part of Operation Epic Fury. Since the current conflict erupted, the only munitions those launchers have been seen firing are Army Tactical Missile System (ATACMS) and Precision Strike Missile (PrSM) short-range ballistic missiles. PrSM has made its combat debut against Iran, and the newly disclosed operational details raise the question of whether an anti-ship version has been fielded.

Over the first 10 days of Operation Epic Fury, American forces destroyed 50 Iranian naval vessels “using a combination of artillery, fighters, bombers, and sea-launched missiles,” Chairman of the Joint Chiefs of Staff U.S. Air Force Gen. Dan “Razin” Caine said at a press conference at the Pentagon this morning. U.S. officials have consistently stressed that the neutralization of Iran’s naval capabilities is a core objective of the ongoing campaign against Iran.

TWZ subsequently reached out for further clarification about what Caine was referring to here when he said “artillery” and for any additional information about the use of those assets against the Iranian Navy. A U.S. official told TWZ that HIMARS were used against Iranian Navy ships, but would not comment on what type of munitions they had fired or which ships were attacked that way.

However, U.S. Central Command (CENTCOM) has released several videos and pictures showing HIMARS operating in support of Operation Epic Fury. As noted, that imagery has only shown them firing ATACMS and PrSM ballistic missiles. CENTCOM has also now explicitly touted the first-ever combat use of PrSM in the current conflict. U.S. officials have yet to confirm where specifically ATACMS or PrSM missiles are being fired from.

Imagery also began circulating on social media yesterday that is said to show an empty ATACMS ammunition ‘pod’ in Kuwait discovered by locals in the midst of ongoing operations against Iran. Wheeled HIMARS launchers, as well as tracked M270 Multiple Launch Rocket Systems (MLRS), fire ATACMS, PrSM, and 227mm guided artillery from pods with standardized dimensions. ATACMS are loaded one to a pod, while pods for PrSM contain two missiles.

A video also emerged online this past weekend showing two HIMARS being employed from a beach in Bahrain. When the footage was captured is unknown. What munitions they see are also unclear.

No evidence has emerged so far that HIMARS are being used to fire 227mm guided artillery rockets, which come six to a pod, in support of Operation Epic Fury. Even new extended-range variants of these rockets can only fly out to around 93 miles (150 kilometers) away, severely limiting the areas in and around Iran they could reach from available launch points in the region, to begin with. For example, the shortest distance between Bahrain and Iranian soil across the Persian Gulf is around 120 miles. The longest ranged variants of ATACMS can hit targets out to around 186 miles (300 kilometers), with PrSM’s maximum range at least 310 miles (500 kilometers).

It should also be noted that there is no known operational variant of ATACMS capable of engaging moving targets, meaning that it would have to be used against stationary ships. This is very possible, as we’ve seen multiple examples of Iranian ships struck in port or while appearing to be at anchor offshore already.

The U.S. Army had pursued an anti-ship version of ATACMS in the past, which would have been capable of targeting vessels on the move. That effort looks to have been subsumed by the development of a ship-killing variant of PrSM featuring an additional seeker, also known as Increment 2.

There have been indications that the U.S. Army has already begun to field PrSMs that can hit ships on the move, though it is unclear if this represents the full planned Increment 2 capability. In 2024, the service announced it had successfully hit a moving vessel with an unspecified version of PrSM in a test exercise in the Pacific. In a report released in 2025, the Pentagon’s Office of the Director of Test and Evaluation (DOT&E) disclosed that the Army had actually “shot two PrSM EOC [early operational capability] missiles at a maritime target in June 2024.” At that time, the service was only known to have reached early operational capability with the baseline version of PrSM, also known as Increment 1.

It is possible that the Army has begun to field Increment 2 PrSMs, at least on a limited level, as well. The Army announced that it had begun initial flight testing of the new seeker system in 2023. Whether or not Increment 1 missiles can be readily converted into Increment 2 versions is also unknown. Like ATACMS, PrSMs without a moving target capability could still be fired at ships that are stationary, as well.

Regardless, Operation Epic Fury looks to be the first known instance of the U.S. military using ballistic missiles to target ships, at anchor and/or on the move, in real combat.

In general, ballistic missiles are especially well-suited to long-range standoff strikes against time-sensitive and well-defended high-value targets based on the speed at which they fly. They also reach especially high velocity as they come down in the terminal phase of flight. This all, in turn, creates additional challenges for enemy defenders attempting to intercept them compared to other kinds of missiles, including some subsonic air-breathing cruise missiles, and compresses the overall time available to react in any way. That speed also gives ballistic missiles an inherent ability to burrow more deeply into hardened targets. This could be particularly valuable when engaging larger and better-armored warships.

The U.S. military has been playing catch-up for some time now when it comes to the development and fielding of anti-ship ballistic missiles, especially compared to the investments that China’s People’s Liberation Army (PLA) has made in this arena. The use now of ballistic missiles against Iranian ships is, in turn, a sign of things to come in other future U.S. operations. PrSM is often discussed as a particularly important new capability in the context of any future high-end fight against China in the Pacific, just on account of its extended range compared to ATACMS. That extra reach would be valuable for engaging targets on land and at sea. TWZ previously highlighted how the use of PrSM in strikes on Iranian targets, in general, could also send signals to other American opponents well beyond the Middle East.

Interestingly, Iran has also spent considerable time and resources developing an array of shorter-range anti-ship ballistic missiles, capabilities that were then proliferated to its Houthi proxies in Yemen. The Houthis became the first in the world to fire anti-ship ballistic missiles in anger in 2023, as part of a campaign against commercial vessels and foreign warships in and around the Red Sea that ultimately stretched into 2025. So far, Iran does not look to have brought these capabilities to bear itself in the current conflict.

If nothing else, HIMARS has now been used in real combat to target enemy naval vessels, very likely with ballistic missiles. In doing so, experience is gained that could be very relevant beyond the current conflict with Iran.

Contact the author: joe@twz.com

The Gulf states have spent years trying to broker peace between Iran and the West: Qatar brokered nuclear talks, Oman provided back-channel diplomacy, and Saudi Arabia maintained direct dialogue with Iran through 2024 and into 2025. Iran attacked them anyway. The idea that the Gulf states have a responsibility, a moral one, to protect Iran from the consequences of its actions because of good neighbourliness is now grotesque in context. Iran did not return good neighbourliness. Iran returned ballistic missiles.

Iran’s position is based on three propositions. First, that Iran acted in lawful self-defence pursuant to Article 51 of the UN Charter; that host countries relinquished territorial sovereignty by allowing US military bases on their territory; and that the definition of aggression in Resolution 3314 justifies the attack on those bases as lawful military objectives. Each of these propositions is legally flawed, factually skewed, and tactically wrong. Collectively, they add up to a legal argument that, if accepted, would ensure that the Gulf is permanently destabilised, the basic principles of international law are destroyed, and, in a curious twist, the very security threats that Iran is reacting to are reinforced.

The self-defence claim does not meet the required legal threshold

The UN Charter, in Article 51, permits the use of force only in self-defence against an “armed attack”, and this term is not defined by reference to the state invoking it. The International Court of Justice, in cases such as Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States) (1986) and Oil Platforms (Iran v. United States) (2003), has interpreted the requirement of an “armed attack” under Article 51 of the UN Charter restrictively. The Court distinguished between the most grave forms of the use of force, which qualify as armed attacks triggering the right of self-defence, and less grave uses of force that do not. Accordingly, not every use of force, such as minor incidents or limited military activities, amounts to an armed attack. In this light, the mere presence of foreign military bases in Gulf states, maintained for decades under defence agreements with host governments, would not in itself constitute an armed attack against Iran.

Necessity and proportionality are also part of customary international law, requiring that self-defence be necessary and proportional. Iran has not demonstrated either. Targeting the territory of other sovereign Arab states in response to the policy decisions of the United States is neither necessary, since diplomatic and United Nations avenues are still available, nor proportional, since it imposes military consequences on states that are not a party to any conflict with Iran.

Critically, Article 51 also has a mandatory procedural element, in that any state employing self-defence is immediately required to notify the Security Council. Iran has consistently evaded this requirement in each of its escalatory actions. While this may seem to be a minor element, it is in fact the means by which the international community is able to verify and check self-defence claims. A state that evades this requirement is not employing Article 51. It is exploiting the language of Article 51.

Iran’s reading of Resolution 3314 is a fundamental distortion

The provision of Article 3(f) of the Annex to United Nations General Assembly Resolution 3314 (XXIX) (1974) states that an act of aggression includes the “action of a State in allowing its territory, which it has placed at the disposal of another State, to be used by that other State for perpetrating an act of aggression against a third State”. Iran could rely on this provision to hold the Gulf states that host United States military bases liable for any act of aggression committed from their territories against Iran. Nevertheless, the mere presence of military bases is not sufficient to hold them to be lawful military objectives; this will depend on their actual contribution to military activities against Iran based on the rules of international humanitarian law.

Thus, such an Iranian reading would be wrong on three distinct legal grounds.

First, Resolution 3314 is definitional in nature. The resolution was adopted to assist the Security Council in determining when aggression has taken place, not to confer upon states the unilateral power to punish states deemed to have committed aggression through the use of force. The resolution itself, in Article 2, asserts the power of the Security Council to make the determination of what constitutes aggression. The self-application of Article 3(f) of the resolution is therefore bypassed altogether.

Second, Article 3(f) speaks of the active launching of an attack, not the passive hosting of a military base. The legal distinction is fundamental. A state, in signing a defence treaty with another and hosting the latter’s troops on its soil, is engaging in a measure of sovereignty. A state, actively launching, coordinating, or enabling military strikes against a third party, is engaged in a different matter altogether. Iran has not credibly shown this latter case. The presence of US troops or bases in the Gulf has been a fact for decades, and this has not constituted armed aggression against Iran under any legal standard.

Third, even if Article 3(f) were applicable, the appropriate course would be to bring the matter to the Security Council, not to launch unilateral military strikes. General Assembly resolutions do not override the Charter. Iran cannot rely upon a non-binding resolution defining terms to override the Chapter VII requirements for the use of force or the clear criteria of Article 51.

Sovereignty cannot be dictated by a neighbour’s strategic preferences

Iran, in invoking the principle of good neighbourliness, asks the Arab Gulf states to deny the United States basing rights. Good neighbourliness is a two-way principle, and it does not allow for interference in the internal affairs of other states, certainly not interference in the decisions of other states simply because they are deemed inconvenient to the interfering state. All UN states possess the inherent right to conclude defence treaties with whomever they choose, and this is so regardless of the opinion of their neighbours.

The asymmetry of Iran’s position is striking and self-disqualifying. Iran itself has active military relationships with Russia and China. Iran arms, finances, trains, and supports the activities of non-state military actors in Lebanon, Syria, Iraq, and Yemen. The Islamic Revolutionary Guard Corps Quds Force operates openly in various states, and this has been extensively documented in United Nations Panels of Experts reports, as well as other international monitoring reports. According to the standards that Iran applies to the Gulf states, any state that hosts the activities of the IRGC, the transfer of Iranian arms, or the coordination of Iranian proxies on its soil would be engaging in aggression against third parties. Iran will not accept this principle when it is applied to itself. A legal principle that is unacceptable to the party to whom it would be applied is not a legal principle at all; it is a political tool.

A doctrine that defeats Iran’s own strategic interests

From the perspective of international relations theory, Iran’s position follows the logic of offensive realism, which seeks to remove the external balancing architecture of regional neighbours by claiming it to be hostile in nature. However, this approach is empirically self-defeating.

Under balance of threat theory, states react to offensive capability, geographic proximity, and aggressive intentions. Iran’s doctrine, in asserting the right to strike any state that hosts forces it perceives as a threat, drives each and every threat variable to maximum levels for each and every state in the region. The obvious consequence, evident in the data, is that the states in the region and external powers are becoming more, rather than less, securely integrated. The Fifth Fleet’s permanent base in Bahrain, the UAE’s negotiations over F-35s, Saudi Arabia’s deployments of THAADs, and Qatar’s expansion of the Al Udeid base are reactions to Iran’s escalation, not causes of it.

From the perspective of constructivism, the legitimacy of a legal argument is also partly based on the normative credibility of the state that presents the argument. The record of Iran’s compliance with IAEA regulations, including the enrichment of uranium to a purity level of 60 percent or more in 2023–2024, interference with inspections, the removal of monitoring cameras, and the overall violation of the non-proliferation regime, has undermined the credibility of the state significantly. A state that is itself a violator of the legal regime cannot claim the role of a law-abiding state seeking protection under the norms of the legal regime.

Iran’s legal rationale was always theoretically wrong. What has occurred since February 28, 2026, has made Iran’s actions morally and politically wrong. Iran did not simply target US military assets. The reality of the situation is now documented and undeniable. Ballistic missiles and drones were launched against Gulf states in the opening days of the conflict. This marked the first time one actor had simultaneously attacked all six GCC states. Iran escalated its attacks in deliberate stages. Day 1: Iranian missiles were fired against military bases. Day 2: Iranian missiles were fired against civilian infrastructure and airports. Day 3: Iranian missiles were fired against the energy sector. Days 3 and 4: The US Embassy in Riyadh was attacked by Iran. International airports in Dubai, Abu Dhabi, and Kuwait were attacked by Iranian missiles, resulting in the suspension of flights throughout the region. Videos from Bahrain documented an Iranian Shahed drone attacking an apartment building. This is not self-defence. This is the collective punishment of sovereign nations that went to extraordinary lengths to avoid the conflict.

The rationale provided by Iran falls flat when one considers the actions Iran itself took. Its doctrine held that only targets involved in the preparation or launch of an attack against Iran were legitimate targets. Civilian airports are not military bases. Hotels in Palm Jumeirah are not military command centres. An apartment complex in Manama is not a weapons storage facility. By Iran’s own stated legal rationale, none of these targets was legitimate, yet they were attacked. This was not a legal doctrine at all; it was a pretext for coercion, and the conduct of war revealed this to be the case.

The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial stance.

The US Ambassador to the United Nations Mike Waltz says striking Iran was necessary to protect American allies, prevent proxy militias, and to ensure that Tehran can never “threaten the world with a nuclear weapon.”