Trump’s Russian Diesel Deal: The Economics of an Energy Illusion

By Matthew Parish

Monday 12 October 2026

There is something peculiarly characteristic of Donald Trump’s approach to international economic relations in his latest announcement that the United States is to acquire substantial quantities of diesel fuel from the Russian Federation. The American President has identified a problem, namely the exceptionally high price of diesel in the United States, and has proposed what appears to be a straightforward commercial solution. Russia possesses enormous hydrocarbon resources, American motorists and commercial transport operators are paying exorbitant prices for fuel, and therefore the two countries should simply agree that Russia will sell America more diesel. In the President’s transactional worldview, this is the sort of problem that ought to be resolved by a telephone conversation between two powerful men, followed by an announcement that a deal has been concluded.

Unfortunately, international energy markets do not operate quite so simply. The price of diesel is not determined by the personal relationships between presidents, nor can refined petroleum products be summoned into existence by diplomatic agreement. They must be manufactured in functioning refineries, transported through an elaborate network of pipelines, storage terminals and maritime facilities, and delivered to consumers who are prepared to pay the prevailing international price. Each of these stages involves economic constraints that cannot readily be circumvented by political enthusiasm. Moreover, the particular circumstances of Russia’s war against Ukraine, combined with the continuing conflicts in the Persian Gulf, render Trump’s proposal considerably less plausible than its superficial simplicity might suggest.

The agreement announced on 9 October 2026 envisages Russia making available approximately 300,000 metric tonnes of diesel immediately, another 500,000 tonnes in November, and a further million tonnes in December. Trump has also spoken of substantially greater Russian supplies becoming available subsequently, depending upon the condition of the country’s refineries. The American administration has relaxed certain sanctions restrictions to facilitate these transactions, provoking criticism from Ukraine and from members of both American political parties. The ostensible objective is to reduce diesel prices before the American congressional elections on 3 November.

Yet before considering the political wisdom of this arrangement, it is necessary to examine whether it makes economic sense. There are at least three distinct questions. Does Russia possess sufficient surplus diesel to fulfil the commitments? Can the promised quantities be transported to the United States economically and within a useful timeframe? And, most importantly, would their arrival have any appreciable effect upon the prices paid by American consumers?

The answers are considerably more complicated than the announcement of the agreement would lead one to believe.

Russia’s disappearing refining capacity

Russia is one of the world’s great petroleum producers, but crude oil and diesel fuel are not interchangeable commodities. Crude oil is extracted from underground reservoirs, whereas diesel is manufactured through refining processes that separate and chemically transform different hydrocarbon fractions. A country may possess immense crude oil reserves while simultaneously experiencing shortages of refined petroleum products. Indeed, this is precisely the predicament into which Russia has increasingly been driven by Ukraine’s campaign against its energy infrastructure.

For much of the war, Russia’s oil industry provided Moscow with an indispensable source of export revenue. Although Western sanctions complicated the sale of Russian petroleum products, substantial quantities continued to reach international markets through alternative commercial arrangements. Russian crude oil was redirected towards Asian customers, while refined products found buyers in countries prepared to maintain commercial relations with Moscow. This trade supported the Russian federal budget and thereby indirectly financed the continuation of the war.

Ukraine eventually recognised that the Russian petroleum industry represented both an economic vulnerability and a military target. Its increasingly sophisticated long-range drones began attacking refineries, pumping stations, storage facilities and export terminals across the Russian Federation. These operations were intended not merely to deprive Moscow of export revenues but also to disrupt the domestic distribution of fuel essential to Russian agriculture, transportation, industry and military logistics.

The results have been substantial. Some estimates suggest that Ukrainian attacks have affected as much as 45 per cent of Russian refining capacity, although such figures must be interpreted cautiously. Refining capacity temporarily disabled by an attack is not necessarily capacity permanently destroyed, and the percentage of installed capacity affected does not translate directly into an equivalent reduction in actual output. Nevertheless, Russian diesel production has suffered, and Moscow has imposed export restrictions intended to protect domestic supplies.

The distinction between petrol and diesel is particularly important. Russia has experienced severe petrol shortages, but its diesel position is less desperate. Russian refineries historically produce more diesel than the domestic economy consumes, partly because the country’s passenger vehicle fleet relies predominantly upon petrol. According to estimates reported by the Financial Times, Russia is currently producing approximately 5.8 million tonnes of diesel monthly, of which perhaps 1.2 million to 2 million tonnes remain potentially available for export.

Consequently, it would be inaccurate to assert that Russia possesses no diesel whatsoever to sell. It may have a genuine exportable surplus, notwithstanding the damage inflicted upon its refining industry. Indeed, seasonal changes in Russian diesel consumption create additional complications: fuel suitable for warmer weather may become less useful domestically as winter approaches, potentially making certain inventories available for export.

However, the existence of a surplus is not equivalent to the ability to deliver any quantity demanded by a foreign purchaser. Russia must maintain sufficient inventories to support its agricultural sector, commercial transportation networks and military operations. It must also accommodate regional differences in fuel availability, the technical specifications of different diesel grades, and the possibility that Ukrainian attacks will continue destroying production and distribution infrastructure.

This last consideration is especially significant. Russia cannot plan its petroleum exports on the assumption that its refineries will remain undisturbed. Every successful Ukrainian strike introduces uncertainty into production schedules, maintenance requirements and transportation arrangements. An agreement to supply diesel several months into the future is therefore partly a wager upon the effectiveness of Ukrainian military operations.

There is a further irony. Trump has presented Russian diesel as a solution to an international shortage partly created by Ukraine’s attacks upon Russian refining infrastructure. Yet those attacks are an integral component of Ukraine’s strategy for resisting Russian aggression. To the extent that Washington’s arrangement requires Russia to restore its refining capacity, it creates a potential conflict between American short-term energy objectives and Ukraine’s long-term military interests.

The geography of diesel

Suppose, nevertheless, that Russia possesses the promised quantities of diesel. How are they to reach the United States?

Diesel cannot simply be transferred from one national economy to another through a financial transaction. It is a physical commodity requiring specialised storage, handling and transportation facilities. The principal means of moving large quantities across oceans is by product tanker, a vessel designed to carry refined petroleum products rather than crude oil.

Russia possesses several potential export routes, including its Baltic terminals and facilities on the Black Sea. Yet neither offers a particularly straightforward connection to American consumers.

Diesel shipped from Baltic ports must pass through the Baltic Sea, the Danish straits and the North Sea before entering the Atlantic. Cargoes originating from the Black Sea must pass through the Turkish straits, cross the Mediterranean and then proceed towards the Atlantic, normally through the Strait of Gibraltar. Both routes involve substantial distances, maritime congestion, insurance considerations and the commercial availability of suitable vessels.

The Black Sea route presents additional complications because Russian energy export facilities have themselves become targets of Ukrainian attacks. In September, Russian diesel and gasoil exports from Black Sea ports reportedly fell to zero for a week, an extraordinary development for a country that had previously been a major supplier to international markets. Although this reflected export restrictions as well as infrastructure difficulties, it illustrates the fragility of the logistical arrangements upon which Trump’s proposal depends.

The practical difficulties do not end when a tanker leaves Russian waters. Maritime transportation requires commercial insurance, financial services, port access, classification compliance and arrangements with companies willing to handle cargoes associated with a heavily sanctioned country. The American sanctions relaxation may remove certain legal obstacles, but it does not automatically eliminate the commercial risks perceived by shipowners, insurers and banks.

Nor can the United States necessarily absorb every Russian cargo without difficulty. American diesel is subject to stringent quality requirements, particularly concerning sulphur content. Imported fuel must comply with applicable specifications, or it may require additional processing or blending. Storage terminals must have sufficient capacity, and the receiving ports must be connected to distribution networks capable of delivering the product to the regions where it is needed.

American diesel consumption is also geographically uneven. The Gulf Coast possesses enormous refining capacity, while the northeastern United States depends more heavily upon deliveries from other regions and international suppliers. The Jones Act, which restricts domestic maritime transportation between American ports to qualifying American vessels, further complicates the movement of petroleum products within the United States. It does not prohibit foreign tankers from bringing Russian diesel directly to an American port, but it can influence the economics of subsequent domestic redistribution.

These considerations mean that the location at which Russian diesel arrives matters almost as much as the quantity delivered.

There is also the elementary question of time. A tanker voyage from Russia to the American Atlantic coast may require several weeks once loading, transit, unloading and commercial arrangements are taken into account. The first promised cargoes cannot be assumed to reach American consumers immediately merely because the two presidents have agreed that they should be supplied.

This distinction is particularly relevant when the announcement occurs only weeks before a congressional election. A political agreement may influence market expectations overnight, but physical fuel cannot cross the Atlantic at the speed of a presidential social-media announcement.

The arithmetic of a supposedly enormous deal

The quantities involved deserve closer examination because political announcements frequently exploit the difficulty ordinary consumers have in interpreting large numbers.

Three hundred thousand metric tonnes of diesel sounds impressive. It is indeed a substantial quantity of fuel. But its significance depends upon the scale of the market into which it is being introduced.

Using an approximate conversion of 7.45 barrels per metric tonne, the initial Russian commitment represents about 2.24 million barrels of diesel. Spread over an entire month, that would amount to approximately 74,500 barrels per day. The subsequent commitment of 500,000 tonnes would represent about 3.73 million barrels, while a million tonnes would amount to approximately 7.45 million barrels.

American distillate consumption runs into millions of barrels every day. The initial Russian consignment therefore represents less than a single day’s American consumption. Even the December commitment, if delivered in full, would constitute only a modest fraction of monthly American demand.

More importantly, the United States is itself a major producer and exporter of diesel. Its refineries manufacture substantial quantities for both domestic consumption and foreign customers. The problem confronting American consumers is therefore not principally that the country lacks the technical capacity to manufacture diesel. Rather, American producers operate within an international market in which foreign purchasers compete for the same products.

If diesel commands exceptionally high prices in Europe or Latin America, American refiners have an incentive to export it. Conversely, if imported diesel becomes available at a sufficiently attractive price, American distributors may purchase it. International trade tends to equalise prices, subject to transportation costs, tariffs, regulations and regional infrastructure constraints.

The crucial question is therefore not simply whether Russian diesel enters the United States. It is whether the agreement increases the total quantity of diesel available to the international market.

If Russia merely redirects cargoes previously destined for Turkey, Brazil or other established customers, the global supply of diesel remains essentially unchanged. Those displaced customers must obtain replacement fuel elsewhere, potentially purchasing supplies that would otherwise have been available to American consumers.

The transaction may rearrange international trade routes without materially increasing the quantity of diesel available worldwide.

This is the economic principle of displacement, and it is central to understanding the limitations of Trump’s proposal.

There is an important qualification. If sanctions or Russian export restrictions have genuinely prevented diesel from reaching international markets, removing those restrictions could increase effective global supply. Likewise, if Russia possesses inventories that would otherwise remain unused, exporting them could provide temporary relief. The agreement is not necessarily economically meaningless.

But the distinction between releasing previously unavailable fuel and merely redirecting existing exports is decisive. Without evidence of a substantial net increase in global supply, there is little reason to anticipate a dramatic reduction in American prices.

The Persian Gulf and the global price of hydrocarbons

The most fundamental weakness in Trump’s diesel strategy concerns the geographical origins of the present international energy crisis.

The continuing conflicts involving Iran and the Persian Gulf have disrupted one of the most important centres of global petroleum production and transportation. The Strait of Hormuz connects the Persian Gulf with the wider Indian Ocean and ordinarily carries an enormous proportion of internationally traded oil and petroleum products. When conflict interferes with navigation through this narrow maritime passage, the consequences extend far beyond the countries immediately involved.

Oil markets are international markets. A disruption affecting supplies from the Gulf raises prices for purchasers throughout the world, including those who obtain relatively little of their petroleum directly from the region.

The mechanism is straightforward. If the supply of crude oil falls while demand remains comparatively stable, purchasers compete for the reduced quantities available. Prices rise until consumption adjusts or additional production becomes available elsewhere. Since petroleum demand is relatively insensitive to price changes in the short term, substantial increases may be necessary to bring supply and demand back into equilibrium.

Diesel prices are affected through two related mechanisms. First, crude oil becomes more expensive, increasing the cost of the principal raw material used by refineries. Secondly, the supply of refined products may itself be disrupted, increasing the premium that diesel commands over crude oil.

This premium is commonly measured through the refining margin, or crack spread. When diesel becomes scarce relative to crude oil, the diesel crack spread increases. Consequently, diesel prices may rise more rapidly than crude oil prices themselves.

The Gulf conflict has affected both crude production and refining operations, while disruptions to maritime transportation have increased shipping costs and complicated the international distribution of petroleum products. Analysis by the Bipartisan Policy Center has highlighted how the interruption of flows through the Strait of Hormuz has particularly affected diesel and aviation fuel, whose prices have risen more sharply than petrol.

The resulting economic problem cannot readily be solved by importing a few million barrels of diesel from Russia.

To understand why, imagine a global market in which the disruption of Gulf production and transportation removes many millions of barrels of petroleum from ordinary commercial circulation each day. An additional Russian diesel shipment equivalent to a fraction of one day’s American consumption cannot compensate for such a disturbance.

The comparison is imperfect because crude oil and diesel are different commodities, and the relevant supply shortages must ultimately be assessed within their respective markets. Nevertheless, the difference in scale illustrates the problem.

There is also an important analytical qualification to the proposition that the Gulf conflicts are responsible for virtually all the recent increase in diesel prices. Ukrainian attacks upon Russian refining infrastructure have themselves reduced international diesel availability, and some energy analysts attribute a substantial proportion of the recent diesel-specific price increase to those disruptions. The precise allocation of responsibility between the Gulf conflict, Russian refinery outages, sanctions and other market factors remains uncertain.

It would therefore be misleading to attribute every additional dollar paid by American truck drivers exclusively to events in the Persian Gulf. The price of diesel reflects several simultaneous supply shocks, and their effects reinforce one another.

Nevertheless, the Gulf conflict remains a fundamental determinant of the wider international hydrocarbon price environment. Even a complete restoration of Russian diesel exports would not necessarily return American fuel prices to their pre-conflict levels while Gulf production, refining and transportation remain seriously disrupted.

The essential problem is that Trump is attempting to address a global supply crisis through a bilateral commercial agreement whose promised volumes are relatively modest.

Can the agreement reduce American diesel prices?

Economic theory suggests that additional supply, other things being equal, tends to reduce prices. It would therefore be wrong to claim that Russian diesel could have absolutely no effect upon American fuel costs.

The more useful question is whether that effect would be sufficiently substantial and durable to matter.

The answer depends upon several variables: the quantity of genuinely additional Russian diesel entering international markets; the speed with which it becomes available; the geographical distribution of shipments; the prevailing state of American inventories; and the willingness of producers and distributors to adjust their prices.

If Russia releases diesel that would otherwise remain unavailable, international prices may decline modestly. American prices could benefit even if the Russian fuel never physically reaches the United States, because additional supplies to other markets would reduce competition for American exports.

This is a particularly important point. In an integrated international market, the economic benefit of Russian diesel does not depend upon its being delivered to an American port. Russian fuel sold to Brazil, for example, may reduce Brazilian demand for American diesel, leaving more American production available domestically.

Indeed, such an arrangement might be more efficient than shipping Russian diesel across the Atlantic to the United States while American refiners simultaneously export their own production to other destinations.

The relevant economic objective should therefore be to increase global supply at the lowest possible transportation and transaction cost, rather than to arrange a politically conspicuous exchange of cargoes between Russia and America.

The initial financial-market reaction demonstrates another distinction between expectations and physical reality. Following Trump’s announcement, the American ultra-low-sulphur diesel refining margin fell, reflecting traders’ anticipation that additional Russian supplies might ease market conditions. Such movements are genuine market responses, but they do not establish that the promised deliveries will materialise or that retail prices will fall by a corresponding amount.

Retail fuel prices incorporate wholesale costs, transportation, storage, distribution margins and taxes. Changes in international market prices are not necessarily transmitted immediately or completely to consumers.

Furthermore, an announcement that temporarily reduces futures prices may have little enduring effect if subsequent events demonstrate that the promised additional supply is unavailable.

There is consequently a substantial difference between influencing the expectations of financial traders and changing the underlying physical balance between global diesel production and consumption. Trump may achieve the former without achieving the latter.

The sanctions paradox

The proposed agreement also raises a more profound question about the economic purposes of sanctions. Since Russia’s full-scale invasion of Ukraine in February 2022, Western governments have sought to restrict Moscow’s ability to finance its military operations through hydrocarbon exports. The precise mechanisms have varied, including import prohibitions, financial restrictions and measures intended to reduce the revenues available to Russian energy companies.

The economic logic is that petroleum revenues provide the Russian state with resources that can support its war effort. Reducing those revenues increases the financial burden of continuing the conflict.

Yet sanctions also impose costs upon the countries applying them. If Russian petroleum products are removed from international markets, the remaining suppliers may command higher prices. Consumers in sanctioning countries can therefore find themselves paying more for fuel, even as the restrictions are intended to weaken Russia economically.

This is not necessarily a contradiction. Economic sanctions are instruments of foreign policy, and their purpose is not invariably to maximise short-term consumer welfare. Governments may rationally accept higher domestic energy prices if they believe the strategic benefits of weakening an aggressor state outweigh the economic costs.

However, the calculation becomes more complicated when international conflicts simultaneously disrupt alternative sources of supply.

The American administration now appears to have concluded that the domestic political costs of high diesel prices justify relaxing restrictions upon Russian exports. This is a significant reversal of the economic logic underpinning earlier sanctions policy.

The consequences for Russia should not be exaggerated. Analysts have suggested that even substantially expanded Russian diesel exports would generate relatively limited additional revenue for the Russian federal budget compared with the enormous costs of the war. The agreement is therefore unlikely, by itself, to transform Moscow’s capacity to finance military operations.

Nevertheless, sanctions possess a political and diplomatic significance extending beyond their immediate financial effects.

By negotiating directly with Vladimir Putin over Russian diesel, Washington potentially reinforces the proposition that Russia remains an indispensable commercial partner whose cooperation is necessary to resolve international economic difficulties. Moscow may regard this recognition as valuable irrespective of the actual revenue generated by the transactions.

There are also unresolved legal questions concerning the extent to which the American executive branch can authorise Russian energy imports in the face of existing statutory restrictions. Members of Congress from both parties have challenged the administration’s approach, while the Treasury Department maintains that the arrangement is lawful. These disputes may complicate the willingness of private commercial actors to participate. The political costs of the arrangement may therefore exceed its measurable economic benefits.

The problem of opportunity cost

There is another economic concept that deserves attention: opportunity cost. Every political initiative consumes resources, administrative attention and diplomatic capital that might otherwise be devoted to alternative policies. The relevant question is not simply whether Russian diesel can provide some additional supply, but whether negotiating with Moscow represents the most effective available means of reducing American fuel prices.

The United States possesses substantial refining capacity, sophisticated petroleum distribution networks and considerable influence over international energy policy. She also maintains strategic petroleum reserves and can coordinate emergency supply measures with other major industrialised economies. Indeed, the Group of Seven has recently agreed to release substantial quantities of emergency oil and petroleum product stocks in response to the energy crisis. Such measures can provide temporary relief, although they cannot permanently replace disrupted production.

The administration could also concentrate upon alleviating logistical bottlenecks, encouraging the efficient distribution of existing inventories and supporting the restoration of international shipping routes.

None of these measures offers an effortless solution. Refineries cannot be constructed overnight, strategic reserves are finite, and maritime security in the Persian Gulf depends upon political and military developments beyond the control of energy economists.

Nevertheless, these alternatives address aspects of the actual supply problem rather than relying upon the assumption that Russia can suddenly produce and deliver sufficient additional diesel to transform American retail prices.

The greatest potential improvement in the international hydrocarbon market would arise from a durable reduction in the disruption of Gulf production and transportation. Restoring confidence in maritime navigation, permitting damaged facilities to resume operations and reducing the geopolitical risks associated with petroleum shipments would address the underlying causes of elevated prices more directly than a limited bilateral diesel agreement.

This is not to suggest that diplomacy in the Gulf would necessarily be straightforward. The conflicts involve competing security interests, regional rivalries and strategic calculations that cannot be reduced to the price of a barrel of oil. But the economic consequences of those conflicts are sufficiently enormous that any serious strategy for stabilising international energy prices must confront them.

The political economy of presidential announcements

Trump’s approach becomes more intelligible when considered not merely as an exercise in energy economics but as an example of political economy.

Political leaders do not necessarily select policies solely because they maximise aggregate economic welfare. They also respond to electoral incentives, public perceptions, institutional constraints and the political advantages of appearing decisive.

Diesel prices possess particular political significance because they affect sectors central to the American economy. Commercial transportation depends heavily upon diesel, as do agriculture, construction and numerous industrial activities. Higher diesel costs are transmitted through supply chains and can contribute to increases in the prices of food, manufactured goods and other consumer products.

The political pressure to reduce those costs is therefore considerable, especially immediately before congressional elections.

A presidential announcement that Russia has agreed to supply millions of tonnes of diesel offers a readily comprehensible narrative. It suggests that the administration has identified a practical solution to a problem affecting ordinary Americans and has obtained the cooperation of a major foreign power.

The underlying economic reality is considerably less dramatic. Russia may possess surplus diesel, but not necessarily in the quantities or locations required. The fuel must be transported through complicated international logistics networks. Some shipments may merely displace existing trade rather than increase global supply. Even genuinely additional volumes may be too small to overcome the consequences of the much larger disruptions affecting international petroleum markets.

Yet these qualifications are difficult to communicate through political slogans. There is a fundamental asymmetry between the simplicity of announcing an energy agreement and the complexity of evaluating whether it will work. The announcement takes minutes; the physical consequences unfold over months. By the time its limitations become apparent, the immediate political benefits may already have been secured.

This is not a phenomenon unique to Donald Trump. Governments throughout history have announced ambitious commercial agreements whose practical effects proved much smaller than their initial presentation suggested. But Trump’s preference for personal diplomacy and conspicuous transactions makes the distinction between political theatre and economic substance particularly pronounced.

Ukraine’s place in the equation

For Ukraine, the agreement presents an uncomfortable strategic dilemma.

The Ukrainian armed forces have invested substantial resources in developing the ability to attack Russian energy infrastructure at considerable distances from the front lines. These operations are intended to impose economic costs upon Moscow and disrupt the logistical foundations of Russia’s military campaign.

The effectiveness of this strategy depends partly upon Russia’s inability to restore damaged facilities quickly enough to maintain normal production and export operations.

If Washington encourages Russia to increase diesel exports while simultaneously seeking to reduce the disruption of Russian energy infrastructure, the United States risks weakening an important element of Ukraine’s economic warfare.

President Volodymyr Zelenskyy’s criticism of the agreement must be understood in this context. Ukraine is being asked, in effect, to accept that the economic interests of American consumers may justify facilitating additional Russian petroleum exports at a time when Ukrainian forces are attempting to reduce those very exports.

From Kyiv’s perspective, the proposition is understandably objectionable. There is, however, a distinction between the economic and strategic consequences of the arrangement. A limited increase in Russian diesel exports may have little measurable effect upon Moscow’s ability to finance the war, while the diplomatic symbolism of American cooperation with Russia may be considerably more damaging.

Equally, Ukraine cannot assume that every reduction in Russian petroleum exports necessarily benefits its strategic position without qualification. Higher global hydrocarbon prices can increase the revenues Russia earns from the oil it continues to export. The relationship between export volumes, international prices and Russian government revenue is therefore not straightforward.

The economic effectiveness of Ukraine’s campaign depends upon the balance between reduced Russian production, higher international prices, repair costs and the broader disruption of Russian commercial activity.

Nevertheless, Ukraine’s objective remains clear: to increase the economic costs of Russian aggression. Trump’s agreement potentially complicates that objective without offering compelling evidence of corresponding benefits to American consumers.

A deal with diminishing returns

The economics of Trump’s Russian diesel agreement ultimately point towards a relatively simple conclusion, although reaching it requires navigating a surprisingly complex network of industrial, logistical and geopolitical considerations.

Russia probably possesses some diesel available for export, notwithstanding the damage inflicted upon its refining infrastructure. The immediate quantities promised are not inherently impossible, although larger commitments may become increasingly difficult to fulfil if Ukrainian attacks continue.

Transporting Russian diesel to the United States is technically feasible, but involves substantial distances, commercial risks, regulatory complications and unavoidable delays. There is no particular economic reason why every additional Russian barrel should physically travel to America if it can more efficiently relieve international shortages elsewhere.

Most importantly, the quantities involved appear insufficient to produce a major or sustained reduction in American diesel prices unless they form part of a much larger restoration of global supply.

The international hydrocarbon market is confronting overlapping disruptions arising from the Gulf conflicts, damage to Russian refining infrastructure, sanctions, transportation difficulties and the limited short-term flexibility of petroleum production and consumption. A bilateral arrangement involving comparatively modest quantities of diesel cannot reasonably be expected to reverse all these forces.

The agreement may produce a temporary reduction in market prices through expectations of additional supply. It may release some genuinely additional Russian fuel into international circulation. It may even provide limited relief to particular regional markets.

But none of these possibilities establishes that American truck drivers, farmers and commercial operators will experience a substantial or enduring reduction in their fuel bills.

The deeper lesson concerns the limits of transactional diplomacy when applied to international commodity markets. Presidents can negotiate agreements, alter sanctions and influence expectations, but they cannot abolish the economic constraints imposed by industrial capacity, geography, transportation costs and global supply and demand.

Trump’s political instincts encourage him to regard international economic problems as opportunities for spectacular bargains. Yet the price of diesel is not a number that Vladimir Putin can simply agree to reduce in a telephone conversation.

It is the outcome of millions of commercial decisions, constrained by the physical realities of petroleum production and shaped by wars whose consequences extend across continents.

There is something almost tragicomic about the spectacle of the United States, one of the world’s greatest petroleum producers and refiners, turning to a Russia whose energy infrastructure is being systematically attacked by Ukrainian drones in the hope of obtaining cheaper diesel. The arrangement illustrates how thoroughly the global energy system has become entangled with the geopolitical conflicts of the twenty-first century.

It also illustrates the limitations of political leadership that confuses the announcement of a transaction with the resolution of an economic problem. Diesel fuel must still be refined, transported, distributed and sold. Tankers must still cross oceans, damaged refineries must still be repaired, and consumers must still compete for scarce petroleum products in international markets.

And so long as the Persian Gulf remains a theatre of conflict and Russian energy infrastructure remains vulnerable to Ukrainian attack, the global market will continue to price diesel according to scarcity and risk rather than presidential optimism. The White House may announce a deal. The international petroleum market will determine what that deal is worth.