On Friday, President Donald Trump announced that he and Russia’s President Vladimir Putin had reached an agreement under which Russia will immediately supply more than 300,000 tons of diesel and an additional 4.5 million tons in stages over the coming months. The Treasury Department accordingly issued a temporary license allowing Russian diesel onto the global market, exempting cargoes loaded on or after that day from sanctions until April 2027. The move undermines U.S. sanctions on Russia that have been in place since the invasion of Ukraine in 2022 and were strengthened less than a month ago by the Lindsey Graham Sanctioning Russia and Iran Act. According to a New York Times report, “most of the ownership in the deal would go to a group of Middle Eastern investors, including some with business ties to key U.S. officials involved in the negotiations.”
In response to the U.S.-Russian deal, Ukrainian President Volodymyr Zelenskyy pointed out that “[t]his only fuels Putin’s war effort and gives him the ability to wage war even more aggressively.” Trump’s response:
I suggest they get a new leader who can make a deal, because he could have made many deals. And for some reason, he never does. That’s a war that should have never started. And I think it’s time for Ukraine to get a new president.
And then he thanked Putin.
The announcement followed a month of public pressure on Ukraine. On September 13th, Trump, speaking at his golf club in Ireland, said Zelenskyy must “stop knocking out diesel fuel in Russia.” He continued, “Let him go after targets, but not diesel fuel, because he’s causing a shortage of diesel fuel.” Trump doubled down following the announcement of the Russia deal: “[Zelenskyy] wants to make problems for the world. He wants to make problems for our farmers, our ranchers, with diesel fuel.”
The pressure has since intensified. On Sunday, Trump declared, “Effective immediately, there is an ENERGY CEASEFIRE in the War between Russia and Ukraine,” and demanded that Ukraine “damn well stop” striking Russian refineries. Zelenskyy responded that “was news for me. But if Russians agree to an energy ceasefire, Ukraine will agree.” He said that Ukraine would halt such strikes if Russia stopped attacking Ukraine’s energy infrastructure, insisting that any de-escalation “must be mutual and with real guarantees.” The Kremlin has not confirmed the arrangement. On Monday, Zelenskyy said, “There were Russian violations of the energy ceasefire announced by President Trump.”
Meanwhile, European governments have rejected Washington’s approach. As the EU’s foreign policy chief, Kaja Kallas, put it, “This is not the time to ease pressure on Russia, and Europe won’t.”
In part, Trump is correct. Ukrainian attacks on Russia’s oil and gas industry have forced Russia to ration fuel and ban diesel exports. But diesel prices have risen nearly 70 percent since the war with Iran began, a conflict of the administration’s own choosing. Moreover, Russia initiated the strikes on oil facilities and related assets in Ukraine. Within weeks of the 2022 invasion, Russian attacks had knocked out Ukraine’s sole fully functioning refinery in Kremenchuk and, by the Russian Defense Ministry’s account, destroyed another near Odesa, together with fuel and lubricants storage. Such attacks have not abated, and Ukraine is predictably responding in kind.
From a security perspective, the deal eases pressure on Russia at a moment when Ukraine’s strikes had begun to bite, with consequences for Ukraine and its European neighbors alike. This article addresses the international law questions the deal raises. It begins with the legal baseline––Russia’s aggression and Ukraine’s right of self-defense. It then examines the legal status of Russia’s diesel facilities under the law of armed conflict (LOAC), including the long-standing U.S. position that “war-sustaining” objects are legitimate military targets. Against that standard, it assesses whether the United States bears responsibility for aiding or assisting Russia’s unlawful use of force, whether the United States helps maintain a situation created by a serious breach of a peremptory norm (the most severe international law violations), and whether the deal is consistent with the law of neutrality.
The Starting Point
The starting point is Russia’s blatant violation of the prohibition on the use of force in Article 2(4) of the UN Charter, which reflects customary international law. Russia violated that prohibition in 2014 by occupying Crimea, an ongoing violation of the UN Charter that was exacerbated when Russian forces launched their so-called “special military operation” in February 2022. Suggesting there was, or is, any legal basis for Russia’s actions would be nonsensical.
Any claim that Ukraine could not respond forcibly under the right of self-defense in Article 51 of the Charter and customary law would be equally unfounded. Under international law, such responses must be “necessary and proportionate,” but in light of the ongoing Russian occupation of wide swaths of Ukrainian territory, attacks on Ukrainian forces, and the constant bombardment of the civilian population, those conditions are self-evidently satisfied (see, e.g., Nuclear Weapons, ¶ 41; DoD Law of War Manual, § 1.11.1.2).
To be clear, Russia’s operations against Ukraine have constituted a continuing “internationally wrongful act” under the law of State responsibility since 2014 (Articles on State Responsibility, art. 2). Ukraine’s forceful response is lawful under that law as taken in a “circumstance precluding wrongfulness” (art. 21). The significance of these legal characterizations will become clear below.
The Legal Character of Diesel-Related Facilities
Trump’s demands that Ukraine “go after targets but not diesel fuel” seem to assume either that diesel is not a lawful target or that Ukraine should forgo attacks on lawful targets when defending itself against Russia’s unlawful attack. More likely the latter. But either way, LOAC rules on “military objectives” govern the legal status of facilities supporting diesel oil exports. Those rules bear directly on the U.S.-Russian deal.
The most important and overlooked point is that if the facilities that produce Russian diesel for export are military objectives, the United States has agreed to underwrite an activity that contributes to Russia’s war. This implicates the United States’ legal responsibility for supporting Russia’s ongoing internationally wrongful act (use of force against Ukraine) and its obligations as a neutral, the status the administration effectively claims for the United States.
Under LOAC, attacks may be directed only at military objectives. Article 52(2) of Additional Protocol I, to which both Russia and Ukraine are party, defines them as objects “which by their nature, location, purpose or use make an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage.” The definition undoubtedly reflects customary international law (ICRC Customary IHL study, rule 8). For instance, the Department of Defense, which is not a party to the instrument, adopts it verbatim in its Law of War Manual (§ 5.6.3), and the United States has explicitly accepted it as customary international law (State Dep’t Legal Adviser, ASIL Remarks 2016).
There is universal agreement that facilities supplying “petroleum, oil, and lubricants” (POL) to the enemy armed forces are military objectives. Thus, to the extent diesel supplies or facilities can be directly linked to fueling, for instance, Russian armored vehicles, logistics transports, or diesel-powered military generators, they are lawful targets. This applies whether they are currently used in military operations or will be in the future, as the definition reflects in its references to “use” and “purpose.” Ukraine has justified many of its strikes on exactly this basis–“to cut off fuel and ammunition supplies to the invading army.” To be clear, demanding that Ukraine abstain from such strikes is to demand that it stop attacking targets that unquestionably qualify as military objectives and that have a direct and significant impact on Russian operations.
However, Ukraine also has broader objectives in its long-range strikes on Russia’s oil refining capacity, which by Kyiv’s account has been cut by more than half. As Ukraine’s Defense Minister has noted, the strikes are “a significant blow to the enemy’s economy.” If that blow is a coincidental byproduct of striking facilities that at least in part affect Russian military operations, there is no legal issue with respect to attacking those targets. Those facilities are themselves military objectives. (How proportionality might apply is a separate question we need not address here.)
The harder case involves diesel facilities whose only connection to the hostilities is the revenue they generate in commercial markets at home or abroad, which in turn funds the war effort. Whether such oil and the infrastructure qualify as a military objective subject to lawful attack is the subject of the long-running “war-sustaining” debate.
On one side are those who assert, as Mike does, that there is no such thing as a “war-sustaining” military objective. In their view, every object must be assessed against the definition of military objective set forth above, and nothing else. Oil used directly to fuel operations of the armed forces qualifies; oil that is not does not become a military objective solely because its sale indirectly funds the war effort. Since nearly all economic activity generates revenue for the State, the war-sustaining approach would have no logical limit (ILA Study Group, report, p. 341). This is the prevailing view among international lawyers.
On the other side are those, like Ryan, who argue that the proper interpretation of the definition of military objective encompasses such targets, and is supported by the negotiating history of Additional Protocol I. For nearly half a century, this has been the official U.S. position. The current U.S. Navy/Marine Corps/Coast Guard Commander’s Handbook on the Law of Naval Operations, for instance, defines military objectives to include objects that “effectively contribute to the enemy’s war-fighting, war-supporting, or war-sustaining capability” (NWP 1-14M, § 8.2). The DoD Law of War Manual explains that the “contribution to military action” of an object “need not be ‘direct’ or ‘proximate.’” For example, an object might make an effective, but remote, contribution to the enemy’s military action and nonetheless meet this aspect of the definition.” And “[m]ilitary action has a broad meaning and is understood to mean the general prosecution of the war” (§ 5.6.6.2). Lest there be any doubt as to the diesel facilities, the Manual lists “[o]il refining and distribution facilities and objects associated with petroleum, oil, and lubricant products (including production, transportation, storage, and distribution facilities)” among economic objects that “have been regarded as military objectives” (§ 5.6.8.5).
The debate need not be settled here. Whatever its merits, the U.S. war-sustaining position is the standard against which the U.S.-Russian deal should be measured. Thus, even if Ukraine strikes diesel-related facilities that do not directly support military operations, those targets are, in the U.S. view (and Russian government view as well), lawful military objectives. That Trump is pressuring Ukraine to take lawful targets off the table as it defends itself therefore raises questions as to U.S. support for Ukraine in the face of Russian aggression.
A U.S. Violation of International Law?
Putting aside the impact on Ukraine’s ability to defend itself, there is no question that the deal will contribute to Russia’s ability to mount unlawful military operations against Ukraine. In that sense, through the sanctions relief and the arrangement it brokered, the United States is facilitating an activity that it, by its own legal characterization, regards as effectively contributing to Russia’s military action. The United States cannot treat oil exports as war-sustaining when it is assessing targets and as ordinary commerce when it is brokering their sale. But does this make the U.S. action unlawful? It does.
Use of Force: The fact that the U.S.-Russia deal will contribute to the unlawful use of force against Ukraine does not mean that the United States is itself responsible under international law for an unlawful use of force. As Casey Biggerstaff and Mike have explained, support to another State that is involved in an armed conflict can “rise to the level of a use of force under Article 2(4) and customary international law,” but “the requisite threshold for what we label the ‘indirect’ use of force is high.” Whether that threshold is crossed depends on factors such as the supporting State’s intent; the timing, directness, and nature of the support; the geopolitical context; and the support’s impact. Economic measures standing alone fall short (p. 194, applying Paramilitary Activities, ¶ 228 by analogy).
Aid or Assistance: A strong argument is that the U.S. action qualifies as “aid or assistance” to Russia’s unlawful use of force. The relevant law is outlined in Article 16 of the International Law Commission’s (ILC) Articles on State Responsibility, which the International Court of Justice found to reflect customary law (Bosnian Genocide, ¶ 420).
A State which aids or assists another State in the commission of an internationally wrongful act by the latter is internationally responsible for doing so if: (a) that State does so with knowledge of the circumstances of the internationally wrongful act; and (b) the act would be internationally wrongful if committed by that State.
Article 16’s two express requirements are readily satisfied. Knowledge is clear. The original 2022 sanctions order rests on a finding of “the Russian Federation’s unjustified, unprovoked, unyielding, and unconscionable war against Ukraine, including its recent further invasion in violation of international law.” And just weeks ago, Trump also signed the Graham Act, in which sanctions against Russia can be terminated only if the President of the United States certifies to Congress that Russia has “ceased all military hostilities against and any activities to overthrow, dismantle, and subvert the Government of Ukraine.” The link between sanctions on diesel is also made clear by Zelenskyy stating that the deal “only fuels Putin’s war effort and gives him the ability to wage war even more aggressively,” which Trump reportedly “shrugged … off.” The EU foreign policy chief also warned, “Suspending sanctions on Russian diesel provides Moscow with more revenues to wage war.” It is also noteworthy that the U.S. intelligence community has detailed that China’s purchasing of oil strengthens Russia’s ability to sustain the war in Ukraine (Annual Threat Assessment, March 2026 p. 21), and Secretary Marco Rubio has criticized India’s purchasing Russian oil because “that is helping to sustain the Russian war effort … and allowing this war to continue in Ukraine” (see also then-Senator Rubio’s 2023 letter to Department of Defense).
What matters for responsibility under Article 16 is knowledge of the facts, not the assisting State’s legal characterization of them. And Russia’s aggression is, as explained, patently a continuing internationally wrongful act, one that would have been no less unlawful had it been mounted by the United States.
A complicating factor is that the ILC’s commentary to the article notes that “the aid or assistance must be given with a view to facilitating the commission of the wrongful act, and must actually do so. This limits the application of article 16 to those cases where the aid or assistance given is clearly linked to the subsequent wrongful conduct.” According to the ILC, “There is no requirement that the aid or assistance should have been essential to the performance of the internationally wrongful act; it is sufficient if it contributed significantly to that act” (p. 66). It adds that, as a general matter, “a State providing financial or other aid to another State should not be required to assume the risk that the latter will divert the aid for purposes which may be internationally unlawful” (p. 65).
The administration can be expected to argue that its purpose in cutting the deal with Russia is to lower diesel prices at home, not to support Russian operations against Ukraine. This is probably true, and on a strict reading, the United States would escape responsibility for aiding or assisting because facilitating Russia’s aggression is a byproduct of the deal rather than its object.
The better view, however, is that purpose is not strictly required. Harriet Moynihan has persuasively observed that “in spite of the fact that the ILC Commentary uses the term ‘with a view to,’ Article 16 does not require purpose on the part of the assisting state, nor does the assisting state have to be in common cause with the principal. Knowledge or virtual certainty that the recipient state will use the assistance unlawfully is capable of satisfying the intent element under Article 16, whatever its desire or purpose” (¶ 70). As former State Department attorney Brian Finucane explained in a 2016 law review article, the ILC position does not foreclose the approach described by Moynihan (see also Goodman & Jackson 2016). Any other reading would allow a State to escape responsibility for knowingly assisting another State’s unlawful use of force simply by pointing to a different motive.
Crucially, this is not a case of aid that might be “diverted.” Military spending accounted for roughly 44% of the Russian budget in the first half of 2026, and the U.S. war-sustaining doctrine itself treats diesel exports as contributing to belligerent military action in such circumstances. The U.S.-Russia deal was also preceded by pressure on Ukraine to stop striking diesel production facilities, pressure that culminated in Trump’s demand that Kyiv “damn well stop,” despite the status of some (and, by the U.S. interpretation, all) of the facilities as lawful targets. Facilitating Russia’s war effort is not a remote risk but the direct consequence of the arrangement. This is a virtual certainty.
It must be cautioned that U.S. responsibility would not extend to Russia’s unlawful use of force itself, for an assisting State “is responsible for its own act in deliberately assisting another State to breach an international obligation by which they are both bound. It is not responsible, as such, for the act of the assisted State” (ASR commentary, p. 67). Notably, “where the assistance is a necessary element in the wrongful act in absence of which it could not have occurred, the injury suffered can be concurrently attributed to the assisting and the acting State” (ASR commentary, p. 67). If the diesel deal is a necessary element for Russia to continue its aggression, one might argue that understanding of responsibility applies to the United States.
The U.S. support would qualify, by the preceding view, as an internationally wrongful act, with all the consequences that follow. By this characterization, the United States is obligated to terminate the agreement and, if circumstances so require, offer assurances and guarantees of non-repetition (ASR, art. 30). It would also be obliged to make full reparation for the injury that the assistance caused Ukraine (art. 31), and, in theory, Ukraine would be entitled to engage in “countermeasures” designed to terminate the U.S. assistance and secure reparations (arts. 22, 49-51). As a practical matter, Ukraine is naturally unlikely to do so, lest it imperil future U.S. assistance or further drive Trump into Putin’s arms. Nevertheless, qualification as an internationally wrongful act would, as a matter of law, trigger these consequences.
Maintaining a Peremptory Norm Violation: The law of State responsibility imposes an independent obligation that applies irrespective of Article 16’s requirements. Article 41(2) provides, “No State shall recognize as lawful a situation created by a serious breach within the meaning of Article 40, nor render aid or assistance in maintaining that situation.” The International Court of Justice has recognized this obligation in multiple cases (Wall, ¶ 159; Legal Consequences, ¶ 279). The ILC Commentaries make clear the obligation does not require the assisting State to share the intent to commit the wrongful act (p. 115; Hathaway and Goodman 2022 (analyzing China’s support for Russia’s aggression against Ukraine)).
Article 40 addresses serious breaches of “peremptory norms,” that is, rules so fundamental that derogation from them is prohibited even with the consent of affected States (Vienna Convention, art. 53). Whether the use of force qualifies as such a norm remains contested, but the prohibition of aggression surely does. This is a point the ILC commentary makes (pp. 112-13). Indeed, the ILC lists it first among peremptory norms in its 2022 Draft Conclusions on Peremptory Norms (annex (a)).
Accordingly, the meaning of aggression looms large. The General Assembly’s Definition of Aggression resolution, parts of which the International Court of Justice has treated as reflecting customary law (Paramilitary Activities, ¶ 195), defines aggression as, inter alia, “the use of armed force by a State against the sovereignty, territorial integrity or political independence of another State” (art. 1). It provides the example of the “invasion or attack by the armed forces of a State of the territory of another State, or any military occupation, however temporary, resulting from such invasion or attack, or any annexation by the use of force of the territory of another State or part thereof” (art. 3(a)).
Russian actions clearly qualify, and there is broad agreement on that point. For instance, the General Assembly condemned “the aggression by the Russian Federation against Ukraine” soon after the 2022 invasion and later that year rejected Russia’s purported annexation of Ukrainian territory. The Trump administration has generally avoided labeling Russia the aggressor, but in September 2025 the President himself acknowledged that “when you are the aggressor, the losses are greater.” Defense Secretary Pete Hegseth has also testified that “Russia is the aggressor” in the conflict.
By acting to increase revenue to a State that devotes roughly 44% of its budget to the military, and which is occupying Ukrainian territory, the United States will be knowingly aiding the maintenance of a situation that clearly violates the peremptory norm against aggression. In doing so, it will itself have committed an internationally wrongful act.
Violation of Neutrality Obligation: The Trump administration has presented the United States as an honest broker outside the conflict, working to end the fighting. It is, therefore, appropriate to assess the diesel agreement against the law of neutrality.
Under the customary law of neutrality, codified in part in the 1907 Hague Conventions V and XIII, belligerents and neutrals have reciprocal rights and duties. According to the DoD Law of War Manual, “The principal duties of a neutral State are to abstain from any participation in the conflict and to be impartial in conduct towards contending parties”(§ 15.3.2). The Commander’s Handbook on the Law of Naval Operations describes abstention as including “the neutral’s duty to abstain from furnishing belligerents with war related goods or services, including money and loans” (§ 7.2).
The law of neutrality does not prohibit neutral states from engaging in commerce with belligerents (NWP 1-14M, § 7.4; see also Hague Convention V, art. 7; DoD Law of War Manual, § 15.3.2.1). But U.S. legal doctrine excludes from “neutral commerce” any that “contribute[s] to the belligerent’s warfighting/war-sustaining capability,” including “exports of products the proceeds of which are used by the belligerent to purchase arms and armaments” (NWP 1-14M, § 7.4). Russian diesel exports would seem to be a paradigmatic case. Nor is the U.S. government a mere bystander to private trade in that commodity, for the U.S. President himself negotiated the arrangement and the government lifted restrictions to enable it.
That governmental role thus engages the duty of abstention. In that regard, a neutral State is “prohibited from providing money or loans to a belligerent State” and must “refrain from placing its various governmental agencies at the disposal of a belligerent in such a way as to aid it directly or indirectly in the prosecution of the war” (DoD Law of War Manual, § 15.3.2.1). On the U.S. interpretation, Russia’s diesel facilities are military objectives precisely because they sustain its war effort. By restoring their export markets and the revenue those markets generate, the United States would appear to be aiding Russia “directly or indirectly in the prosecution of the war.” Reconciling such conduct with the duty of abstention is, at a minimum, difficult.
Concluding Thoughts
The United States has long insisted that objects sustaining an enemy’s war effort are lawful targets. Measured against that position, Russia’s diesel facilities are military objectives, and the deal that restores their export markets is not ordinary commerce. The United States would not thereby be using force against Ukraine. But by knowingly facilitating Russia’s war, it will arguably bear responsibility for aiding or assisting Russia’s unlawful use of force. The United States also bears legal responsibility for helping maintain the situation Russia’s aggression created. And the United States is acting in a manner difficult to reconcile with the neutrality it effectively claims. In each case, the United States’ legal exposure flows from its own legal characterizations. Having long treated such economic activity as integral to an enemy’s capacity to wage war, it can hardly treat the same activity as legally neutral when it is the one enabling it. Putting law aside, the U.S. action is strengthening Russia’s hand in its war of aggression.
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