Strait of Hormuz escalation risk

President Donald Trump said on April 12 that the United States would begin a naval blockade tied to the Strait of Hormuz after weekend peace talks with Iran collapsed. (cnbc.com) Trump said the talks in Islamabad ran more than 21 hours without a deal, and Reuters reported on April 13 that United States military officials then shifted the operational plan to blocking maritime traffic entering and exiting Iranian ports and coastal areas starting Monday. (cnbc.com) (reuters.com) That distinction matters at sea. The Strait of Hormuz is the only ocean outlet for the Persian Gulf, and the shipping lanes are just 2 miles wide in each direction with a 2-mile buffer zone between them. (britannica.com) (iea.blob.core.windows.net) The waterway carries too much energy trade for markets to ignore. The United States Energy Information Administration said flows through Hormuz averaged 20 million barrels a day in 2024, equal to about 20% of global petroleum liquids consumption, and about one-fifth of global liquefied natural gas trade also passed through it. (eia.gov 1) (eia.gov 2) Prices moved fast when trading reopened. CNBC reported United States crude futures rose more than 8% to about $104.8 a barrel early April 13, and other market reports showed Brent crude above $102. (cnbc.com) (thehindu.com) Shipping reacted before any broad enforcement began. Reuters said tankers were steering clear of the strait on April 13, and the Associated Press reported Lloyd’s List intelligence saw the blockade announcement halt the limited traffic that had resumed after the ceasefire. (reuters.com) (apnews.com) The risk is not only higher fuel costs. Qatar sends most of its liquefied natural gas exports through Hormuz, and the Energy Information Administration said 83% of the liquefied natural gas moving through the strait in 2024 went to Asian markets. (eia.gov) Iran has used the strait as leverage for years, but the current disruption is already deeper than a routine standoff. Lloyd’s List said more than 600 vessels were still stuck in the Gulf as of April 9, and a maritime security advisory said normal traffic is about 138 vessels a day. (lloydslist.com) (mscio.eu) International law also hangs over the wording. Legal experts and historical precedent treat a blockade as an act of war, which is why the Kennedy administration used the word “quarantine” during the Cuban Missile Crisis instead. (msn.com) What happens next depends less on Trump’s post than on how the Navy enforces it and how Iran responds. Even a narrower operation around Iranian ports has already pushed oil above $100 and cut traffic through one of the world’s busiest energy chokepoints. (apnews.com) (cnbc.com)