Twenty minutes after the US naval blockade of Iranian ports took effect on Monday evening (Israel time), a Chinese-owned tanker called the MV Rich Starry pulled out of anchorage near Sharjah and headed for the Strait of Hormuz. It was flying a Malawian flag, which is an interesting choice for a landlocked country. Its AIS transponder had been spoofing its position for 11 days. It carried roughly 250,000 barrels of methanol, officially loaded at a UAE port, almost certainly originating from Iran.
The Rich Starry turned back. Then, in the early hours of Monday, it tried again and slipped through.
That single tanker tells the story of this blockade better than any Pentagon briefing. The US has assembled its largest naval force since 2003: three carrier strike groups, 21 warships, 100-plus aircraft, 10,000 personnel. Iran’s navy is gone. The strait is under American control. And the ship that tested it was Chinese within minutes.
The blockade runs through Beijing
China purchases between 80% and 91% of Iran’s total crude oil exports. In 2025, that meant roughly 1.38 million barrels per day. A decade ago, Iran exported to more than 20 nations. Round after round of sanctions shrank that buyer pool to one.
That concentration is why the blockade can work. Oil funds approximately 45% of Iran’s government budget, and the IMF pegs the fiscal breakeven at $121 to $124 per barrel. Chinese buyers pay around $60 after discount. Iran was running deficits before the blockade began. The rial had lost 15% in one month.
The blockade does not need to stop every barrel. It needs to make the cost of continuing the trade higher than the cost of stopping it, and it needs to present Beijing with a menu where every option serves American interests.
Beijing’s three choices
China can confront the US Navy, running tankers through the blockade and daring destroyers to board them. This would crater energy markets and risk military escalation. Beijing knows this.
China can absorb the loss and buy replacement crude. Painful. Shandong’s independent refineries, which process 90% of Iranian oil reaching China, depend on below-market prices. Replacement barrels would cost $10 to $12 more per barrel. Russia has ramped up deliveries, but the switch carries real cost.
Or, and this is what Washington is banking on, China can use its leverage as Iran’s sole meaningful customer to pressure Tehran toward a deal. Iran will ignore American threats. Iran will pay attention when its only paying customer calls and says: take the terms before the ceasefire expires on April 21.
The Pentagon claims no ships passed the blockade on day one. The facts are more complicated. BBC Verify identified four Iran-linked and three sanctioned vessels that emerged from the strait after enforcement began. The Rich Starry made it through. No Chinese vessel was boarded, seized, or fired upon.
The shadow fleet that moves Iranian oil was built for exactly this game: false flags, spoofed transponders, and ship-to-ship transfers off the coast of Malaysia. China’s customs records show zero imports from Iran since 2022, yet its recorded “Malaysian” crude imports in 2025 reached 1.3 million barrels per day, more than double Malaysia’s entire production. That evasion network has been running for years.
The US has tools to escalate: secondary sanctions against Chinese banks and tanker seizures modeled on December’s Operation Southern Spear. Whether Washington will use them against Chinese entities during a trade war is another question. Critics have a strong argument: CSIS cautioned that the Navy’s inability to prevent Iran’s initial closure of the strait has weakened the administration’s bargaining position, and no allied nation has supported the blockade.
What to watch before April 21
The ceasefire expires in six days. If the shadow fleet pulls back from the strait in the next 72 hours, Beijing has made its decision. If more Rich Starrys probe the blockade, Beijing is calling Washington’s bluff. Watch the rial: if the currency collapse accelerates, internal pressure on the regime becomes harder to ignore.
China holds 1.3 billion barrels in strategic reserves, enough for 120 days. Beijing can survive without Iranian crude. The question is whether it wants to while 21 warships sit between its tankers and their cheapest supplier, and the ceasefire clock runs out.
Every warship in the strait is there to make one phone line ring: the one between Beijing and Tehran.
