Beyond Brent: Why Diesel and Jet Fuel Matter for Southeast Asian Energy Security
When crude oil is only part of the story
For decades, one number has dominated discussion of oil markets:
The price of crude oil
Brent rises and we talk about an energy crisis. Brent falls and we assume the pressure is easing.
But this can be misleading.
Businesses, consumers and most of the economy do not consume Brent crude.
They consume the products made from it.
Diesel moves trucks, mines, plantations, construction equipment, fishing fleets, generators and factories.
Jet fuel moves passengers, tourists, executives, air cargo and high-value exports.
The distinction becomes critical when the bottleneck moves from crude-oil supply to refining capacity and refined-product availability.
That is what we are seeing in 2026.
The oil market is increasingly confronting a downstream problem.
And Southeast Asia needs to pay attention.
Crude oil and diesel are not the same market
Consider what is happening now.
On 16 September 2026, Brent crude was trading at approximately US$107 per barrel.
Yet diesel has become dramatically more expensive.
U.S. diesel has recently exceeded US$6 per gallon at the retail level, while diesel refining margins have reached exceptional levels.
And this is no longer primarily an American or European phenomenon.
On 16 September, the refining margin for Asian 10-ppm diesel exceeded US$87 per barrel, an all-time high. Before the current conflict, it had been around US$22 per barrel.
That difference matters.
A diesel crack spread is not the same as a refinery's net profit. It is essentially a market indicator of the value of converting crude oil into diesel.
When that margin becomes extraordinarily large, the market is telling us something:
the scarce commodity is increasingly not simply crude oil. It is usable refined fuel.
The energy chain is longer than Brent
The actual economic chain looks something like this:
CRUDE OIL
↓
REFINING
↓
DIESEL / JET FUEL / OTHER PRODUCTS
↓
STORAGE
↓
SHIPPING
↓
FREIGHT + INSURANCE
↓
DISTRIBUTION
↓
TAXES OR SUBSIDIES
↓
FINAL ECONOMIC COST
That final number is what matters to the truck operator, mine, airline, factory, plantation, fishing company and government.
Consequently, crude prices can fall while the delivered cost of diesel rises.
There can even be plenty of crude sitting in tanks while the economy struggles to obtain affordable diesel.
Why has the problem moved downstream?
Several pressures have converged.
1. Refining capacity has been disrupted
Russia and the Middle East have historically been major suppliers of diesel to international markets.
Refinery damage and export restrictions have sharply reduced those flows.
By August 2026, combined net diesel exports from Russia and the Gulf were about 1.6 million barrels per day below February levels. Before the two conflicts escalated, the regions represented almost 45% of global seaborne diesel trade.
This is a refining problem that additional crude production alone cannot solve.
2. Refineries are already running hard
High diesel margins encourage refiners elsewhere to maximise production.
But refinery capacity cannot be created overnight.
Complex refineries require sophisticated processing units, maintenance, feedstock and specialised personnel.
Even damaged refineries that cease being attacked may take months to repair.
3. The right crude matters
Not every barrel of crude produces the same product yield.
Refinery configuration and crude quality influence how much diesel, jet fuel, gasoline and other products can be produced.
The question therefore becomes more sophisticated than simply:
How many barrels of crude are available?
We also need to ask:
What type of crude is available, where is the refinery, and what products can it economically produce?
4. Logistics have become part of the price
A barrel of diesel theoretically available in Asia is not automatically a barrel available in Europe.
Someone needs a vessel.
Someone must finance the cargo.
It needs insurance.
The product must meet specifications.
Ports and terminals must be available.
And the shipping route must remain viable.
Hormuz, the Red Sea and other chokepoints therefore influence the final cost of fuel even when physical product exists somewhere in the system.
Diesel is only half the middle-distillate story
Jet fuel deserves much more attention.
Diesel and jet fuel are both middle distillates.
Although they are different products with different specifications, they compete within the broader refinery product slate.
This creates another vulnerability for Southeast Asia.
The region depends heavily on aviation.
Consider:
Singapore as a major international aviation hub;
Thailand's dependence on tourism;
Indonesia and the Philippines as archipelagic economies;
Malaysia's regional aviation connections;
Vietnam's rapidly developing tourism and aviation sectors;
and the importance of air cargo to electronics and other high-value supply chains.
The transmission mechanism is straightforward:
JET FUEL
↓
AIRLINE COST
↓
AIRFARES + SURCHARGES
↓
TOURISM + BUSINESS TRAVEL
↓
AIR CARGO
↓
TRADE + INFLATION
This is why I increasingly regard the present situation as a middle-distillate crisis, rather than simply a diesel problem.
Diesel moves the economy on the ground.
Jet fuel connects it through the air.
Singapore: Southeast Asia's energy bellwether?
One of the indicators I believe deserves much more attention is surprisingly simple:
Singapore's retail diesel price.
Singapore occupies an unusual position in Southeast Asia.
It is a major global oil trading and refining centre, but its domestic retail market also allows international fuel-market pressures to become relatively visible.
On 14 September 2026, posted diesel prices at several major Singapore retailers moved above S$4 per litre.
Caltex reached S$4.07 per litre, while Shell and Esso were at S$4.03 before discounts.
That makes Singapore potentially useful as more than another country in a regional fuel-price table.
Singapore may be Southeast Asia's energy-price bellwether.
The transmission chain is:
GLOBAL CRUDE MARKET
↓
ASIAN REFINING MARGINS
↓
SINGAPORE PRODUCT MARKET
↓
FREIGHT + DISTRIBUTION
↓
SINGAPORE RETAIL PRICE
↓
VISIBLE ECONOMIC PRESSURE
But this also creates an interesting comparison with neighbouring countries.
Singapore shows the price shock. Subsidised markets may show the fiscal shock.
Suppose Singapore diesel rises sharply while regulated or subsidised diesel prices in another Southeast Asian country barely move.
It would be easy to conclude that Singapore has experienced the energy shock while its neighbour has escaped it.
That conclusion may be wrong.
The cost has not necessarily disappeared.
It may simply have changed payer.
Instead of motorists paying the full increase at the pump, some of the cost may be absorbed by:
government budgets;
national oil companies;
fuel distributors;
subsidy programmes;
industrial consumers;
or eventually taxpayers.
There are therefore effectively two prices worth watching:
The international economic cost of diesel
and
the politically visible retail price.
The difference between them can become an important fiscal indicator.
That leads to a useful regional monitoring principle:
Singapore shows us the price shock. Subsidised markets may show us the fiscal shock.
A widening gap between Singapore's market-linked retail diesel price and administered prices elsewhere could therefore provide an early warning of growing subsidy and fiscal pressure.
China is the regional wild card
Southeast Asia also has an important advantage that Europe does not have to the same degree:
China's enormous refining system is nearby.
Higher exports from China, Korea and Japan had helped keep Asian diesel markets better supplied than their Western counterparts.
But that protection is weakening. Asian diesel refining margins have now risen above US$87 per barrel as concerns about regional supply intensify.
China can therefore act as an important pressure-release valve.
If Beijing permits additional refined-product exports, more diesel can enter regional markets.
But China's refining capacity should not be confused with an unconditional guarantee of supply.
Energy security is ultimately a policy decision.
If Beijing decides domestic requirements take priority, export policy can change.
For Southeast Asia, Chinese product-export policy therefore deserves almost as much attention as Chinese crude imports.
Seven indicators Southeast Asia should watch
Watching Brent remains important.
But it is no longer enough.
For a more complete picture of Southeast Asian energy risk, I would monitor:
1. Diesel crack spreads
Particularly Singapore/Asia, Europe and the United States.
2. Diesel inventories
Stocks tell us whether high prices are actually rebuilding the supply buffer.
3. Jet-fuel inventories and margins
Especially important for aviation- and tourism-dependent Southeast Asian economies.
4. Refinery utilisation and outages
The world can have adequate crude supply and inadequate refining capacity.
5. Chinese refined-product exports
Potentially one of Asia's most important marginal supply variables.
6. Freight, insurance and chokepoints
Hormuz, the Red Sea and tanker availability increasingly determine the delivered price.
7. Singapore retail diesel
Potentially Southeast Asia's most visible real-world indicator of how global fuel-market stress is reaching the regional economy.
The question businesses should be asking
The traditional question is:
What is happening to the oil price?
For many Southeast Asian businesses, that question is now insufficient.
A mining company should be asking what is happening to its delivered diesel cost.
An airline should be watching jet fuel.
A plantation should consider fuel embedded in harvesting and transportation.
A logistics company needs to understand diesel exposure.
A manufacturer should consider fuel and freight embedded throughout its supply chain.
And governments need to understand not merely the pump price but the potential fiscal exposure created by suppressing it.
The better question is therefore:
What is happening to the energy products our economy actually consumes - and who ultimately pays for them?
That is a much more useful question than simply asking where Brent closed yesterday.
The energy crisis has moved downstream
Brent remains important.
But Brent is only the beginning of the chain.
The emerging energy-security challenge lies increasingly in the ability to:
obtain the right crude,
process it through the right refinery,
produce enough diesel and jet fuel,
move those products through increasingly difficult logistics chains,
and deliver them to consumers at an economically sustainable price.
That is why I am now watching diesel cracks, jet fuel, refinery operations, inventories, Chinese exports, freight, insurance and Singapore retail prices alongside crude.
Singapore may be the regional bellwether.
Diesel is the warning signal.
Jet fuel tells us the problem extends beyond the road economy.
And the central message is becoming increasingly difficult to ignore:
The energy crisis has moved downstream
About the author
Peter Cockcroft is an energy adviser with more than four decades of international experience across oil and gas, energy investment, project development and government advisory work. His current work focuses on Southeast Asian energy security, energy geopolitics, investment and the commercial consequences of changing global energy markets.
