What Happens if Iran Blocks the Strait of Hormuz?

TL;DR

Blocking the Strait of Hormuz would crash the global economy by cutting off 15% of humanity's entire energy supply.

Key Points

• 1.The strait is only 30 miles wide with two 2-mile shipping lanes, yet ~15% of the world's energy passes through it daily
• 2.The Persian Gulf holds ~50% of Earth's proven oil reserves and ~40% of its natural gas reserves across 8 nations
• 3.China imports 45% of its oil from Gulf states; Japan sources nearly 80% of its energy from Gulf tankers; South Korea imports ~70% of its oil from the Gulf
• 4.Existing bypass pipelines (Saudi Arabia and UAE) can only reroute a maximum of 20% of Gulf oil — Kuwait, Qatar, Bahrain, and Iraq have no bypass at all
• 5.Iran's realistic blocking strategy relies on thousands of maritime mines and coastal missile batteries, not its navy or air force, which can't match U.S. power
• 6.The U.S. Fifth Fleet in Bahrain (15,000+ sailors, 2 aircraft carriers) exists specifically to keep the strait open; Iran and the U.S. nearly went to war in 2019–2020 over Persian Gulf tensions