South Korea eases diesel curbs as Asia rethinks fuel security

South Korea will let its refiners export more diesel from November, the latest sign that Asian governments are easing wartime fuel controls only as far as their own supplies allow.

Refiners may ship up to 110% of the diesel they exported in the same month a year earlier, up from 100% now, Yonhap reported on October 29. The Ministry of Trade, Industry and Resources attached conditions: the higher ceiling applies only to refiners that meet their obligations to the home market and hold adequate stocks.

"With tensions in the Middle East lingering, the government will closely monitor the supply of petroleum products and immediately reinstate the previous cap should further supply concerns arise," a ministry official said.

Since the Iran war disrupted Gulf shipping through the Strait of Hormuz, Asia's fuel policy has rested on keeping barrels at home. The region is now feeling its way towards something more flexible, where exports are rationed month by month, released when tanks are full and withdrawn the moment they are not. Fuel has become an instrument of state policy rather than a commodity left to traders, and the few countries with spare refining capacity hold the cards.

Seoul is the clearest case. It capped product exports in March, alongside a domestic oil price ceiling, and as recently as mid-October it turned down refiners who argued the home market was well supplied. Their case was strong. Diesel made up 27.6% of South Korea's petroleum product output last year and 59.9% of it went abroad, while the Singapore complex refining margin averaged $18 in the third quarter against a break-even of $4-5, according to Yuanta Securities Korea. The Korea National Oil Corporation's own Petroleum Information Center warned on October 13 that Seoul's restrictions "could exacerbate international price increases".

A 10-percentage-point increase will not ease that much pressure. The International Energy Agency estimates that diesel exports from the Gulf fell from about 1.6mn barrels a day (b/d) before the war to roughly 400,000 b/d in August, and Russia has kept its diesel at home as drone strikes hit its refineries.

China, the region's largest refiner, runs a tighter version of the same system. Beijing halted most fuel exports over the October 1-7 Golden Week holiday and then approved about 3.7mn tonnes for the month, against more than 4mn tonnes in September and 4.6mn tonnes in August. "International markets are an afterthought," Michal Meidan, head of China energy research at the Oxford Institute for Energy Studies, told Reuters at the start of the month.

Importers are left bidding against each other. China's October cutback has added to the strain on Asian fuel markets, with Brent near $115 a barrel on October 29, broker IC Markets said in its Asia outlook.

Japan, short of refining capacity to spare, is using its balance sheet instead. Ambassador Ishizuki Hideo and Cambodia's Deputy Prime Minister Prak Sokhonn signed an exchange of notes on October 27 for a $200mn emergency loan to steady the Cambodian economy and secure its energy supply, co-financed with the Asian Development Bank. The money comes through POWERR Asia, the Partnership on Wide Energy and Resources Resilience Asia that Prime Minister Sanae Takaichi launched in April with about $10bn of financial cooperation to help Asian governments pay for crude and fuel and keep supply chains running. Bangladesh received the first loan under it in June, worth up to JPY50bn ($312mn at the time).

Cambodia has no refinery to protect, so its problem is paying for imports at wartime prices while tourism suffers; the Asian Development Bank has cut its 2026 growth forecast for the country to 3.9% from 4.1%.

Seoul has made its relaxation conditional and reversible, Beijing ties exports to domestic stock levels, and Tokyo is buying influence in Southeast Asia by paying other countries' fuel bills. Governments now decide how much fuel crosses their borders and revisit the decision every month. That will last as long as Gulf supply stays short, and every loosening comes with the proviso that the tap can be shut again.