The US Navy's destruction of Iranian oil tankers near Kharg Island last week is expected to deal a significant blow to China's crude oil supply chain, going well beyond the decade-long financial sanctions that Beijing had successfully circumvented, according to an analysis published in Modern Diplomacy. The strike marks the first time Washington has directly targeted the physical infrastructure feeding Chinese refineries.

Why Kharg Island Makes This a Turning Point

Kharg Island serves as the loading terminal for 90 per cent of Iran's oil exports. Striking tankers at this chokepoint is categorically different from earlier financial measures — it physically removes vessels from a supply chain that cannot be quickly reconstituted. As the article notes, ships that have sunk to the bottom of the sea cannot be replaced on short notice.

This comes amid an already strained global oil market, with the Strait of Hormuz chokepoint reportedly under pressure, reducing overall supply availability. The teapot refineries were already running low on stocks even before last week's naval strikes.

China's 'Teapot' Refineries at the Centre of the Crisis

The bulk of Iran's discounted crude has been absorbed by China's smaller independent coastal refineries, colloquially known as 'teapot' refineries. These facilities account for 25 per cent of China's total petroleum product output and have built their entire business model around sourcing sanctioned crude — Iranian, Russian, and Venezuelan — at steep discounts that larger state refiners would not touch.

According to the Modern Diplomacy analysis: Unlike China's state oil majors, which avoid sanctioned crude to protect their access to Western banks and capital markets, teapots built their business model on the opposite trade: buying Iranian, Russian and Venezuelan oil at steep discounts state refiners won't touch.

How China Dodged Sanctions — Until Now

For years, teapot refineries sidestepped US financial sanctions by routing payments through China's own payment rails and barter-style clearing arrangements, effectively bypassing dollar-denominated transactions. With backing from the Chinese government, this system allowed them to absorb nearly all the crude Iran was still able to export.

However, the physical destruction of tankers represents a qualitatively different challenge. Financial workarounds cannot conjure replacement vessels overnight, and the analysis argues that no domestic substitute is available at comparable prices.

Thin Margins Leave Teapots Exposed

Teapot refineries reportedly operate on extremely thin margins that are almost entirely dependent on the discounted price of sanctioned crude to remain competitive against better-capitalised state oil companies. Once that discount evaporates — whether through supply disruption or the destruction of the tankers carrying it — the economics of their operations become unviable.

The cumulative pressure of tanker losses and the Hormuz supply squeeze means the impact on Chinese refining capacity is expected to be felt sooner rather than later, according to the analysis. How Beijing responds — diplomatically, commercially, or otherwise — is now a question that energy markets and geopolitical analysts will be watching closely.