Global Oil Supply Routes

The Strait of Hormuz remains the master variable for global oil. After the conflict that began in late February 2026 effectively closed it, the EIA assumed Hormuz stayed shut into late May, with traffic only beginning to pick up in June. Iran now says the strait will reopen only under new conditions — including possible transit fees set with Oman — which Washington opposes and Oman has reportedly declined to support. Iran describes the strait as open, but in practice only a handful of crude, product and LNG vessels have exited recently — often with AIS gaps or under heightened risk — while overall Gulf flows stay far below normal. Open on paper, restricted in practice.

Hormuz is Washington's top priority and Tehran's main leverage in unresolved US–Iran talks, alongside sanctions, frozen funds and nuclear limits. The early-June Israeli strike on Iran's Mahshahr petrochemical complex — the first hit on Iranian energy infrastructure since the April ceasefire — put a direct energy-asset risk premium back on top of the chokepoint risk. Even after a reopening, recovery is slow: Kuwait says it could restore about 70% of output within 6–8 weeks, the rest taking roughly another month. The Red Sea/Suez route remains independently disrupted by Houthi attacks.

The Suez Canal carries around 5.5 mb/d of oil and petroleum products plus significant LNG volumes. Red Sea avoidance by commercial tankers has kept Canal transit volumes far below pre-disruption levels since late 2023. Cape of Good Hope diversion remains the operating norm for Gulf-to-Europe cargoes. With Hormuz still constrained, both primary Gulf-to-Europe export corridors remain under simultaneous pressure.

The Sumed pipeline can carry approximately 2.5 mb/d of crude as a bypass but not refined products. EU member states have largely adapted sourcing to Atlantic Basin suppliers, but at sustained higher cost. A Houthi ceasefire remains the necessary condition for Red Sea/Suez recovery.

The southern entrance to the Red Sea remains actively disrupted by Houthi attacks since November 2023. Around 4.5 mb/d of oil and products normally transits this route; daily traffic through Bab-el-Mandeb and Suez Canal remains far below pre-attack levels. With Hormuz also still constrained, both primary Gulf export corridors remain under simultaneous pressure.

Operation Prosperity Guardian has not restored commercial transit confidence. Insurance premiums for Red Sea passage remain prohibitive. The Houthi threat is geopolitically linked to the broader US-Iran-Israel conflict; renewed Houthi threats in the Red Sea are an active watch-item alongside the constrained Hormuz corridor. Red Sea normalisation requires a separate Houthi ceasefire.

Chinese naval and coast guard vessels have established a blockade around Scarborough Shoal, disrupting Philippine maritime access and raising the risk of broader interference with commercial tanker traffic through the South China Sea. The sea lane carries approximately 3.4 mb/d of oil — primarily Middle Eastern crude transiting to China, Japan, and South Korea — along with significant LNG volumes. While the blockade is currently focused on the Shoal itself rather than the main tanker lanes, the escalation introduces material operational risk to one of the world's busiest energy corridors.

The Scarborough Shoal has been a flashpoint in China-Philippines tensions since China effectively seized control of the feature in 2012. The current blockade escalates well beyond previous stand-offs and has drawn US statements under the Mutual Defense Treaty with the Philippines. A full closure of the broader South China Sea to commercial traffic — while not the current situation — would represent one of the most severe supply shocks in modern history, affecting roughly a third of global seaborne oil trade. The situation is being monitored by the IEA and has been noted in recent IMF growth revisions.

The only maritime access to the Baltic Sea. Pre-sanctions, around 3 mb/d of Russian crude and products from Baltic ports (Primorsk, Ust-Luga) transited this route. Post-2022 sanctions have reduced Russian flows but shadow fleet tankers continue to carry Russian oil, raising insurance and environmental concerns.

Denmark and Sweden are both NATO members and have shown willingness to scrutinise shadow fleet tanker transits. The EU has progressively tightened enforcement of price cap rules on Russian oil transiting these waters. Several shadow fleet vessels have been detained or refused port access in the region.

The Bosphorus and Dardanelles control Black Sea access to the Mediterranean. Around 2.4 mb/d passes through — primarily Kazakhstani crude via the CPC pipeline and residual Russian Black Sea exports. Turkey has periodically restricted passage, citing insurance requirements linked to Western price cap enforcement on Russian oil.

Turkey operates transit rights under the 1936 Montreux Convention. The EU price cap on Russian oil has created ongoing legal and commercial friction around insurance requirements for vessels. Turkey has resisted pressure to fully enforce EU-aligned restrictions, creating a persistent compliance gap.

The Amsterdam-Rotterdam-Antwerp (ARA) complex is Europe's largest refining and oil storage hub, handling around 4 mb/d of crude and products. It acts as the primary pricing and distribution point for Northwest European fuel markets. Rotterdam alone is the world's largest port by cargo volume. Note: shipping around Antwerp was partially halted on 10 April 2026 following an oil spill; this is an operational incident under containment rather than a structural supply route disruption.

ARA commercial storage acts as a buffer for European supply disruptions. Tanker arrivals at Rotterdam are a leading indicator of fuel availability. ARA stock levels are published weekly by Insights Global and monitored closely by energy traders. In the current environment, ARA stock drawdown is the key metric to watch for early signs of downstream tightness.