By SCM Foreign Correspondent
WASHINGTON — President Donald Trump announced on Monday that the United States would immediately establish a targeted naval blockade aimed exclusively at Iranian shipping, while simultaneously demanding a 20 percent security fee on all other commercial cargo passing through the strategically vital Strait of Hormuz.
The surprise directive, unveiled in a series of characteristic, high-stakes posts on Truth Social, represents a significant escalation in Washington’s efforts to isolate Tehran economically and assert unilateral American control over one of the world’s most critical maritime chokepoints.
“We are reinstating THE IRANIAN BLOCKADE, so named because it is only stopping Iran’s ships or customers from entering or leaving,” Mr. Trump wrote. He sought to reassure global energy markets—which frequently convulse at the threat of instability in the Persian Gulf—that global commerce would otherwise proceed unhindered. “The Hormuz Strait is OPEN, and will remain OPEN, with or without Iran,” he added.
Beyond targeting Iranian vessels, the president introduced a highly controversial financial mechanism intended to offset the cost of the beefed-up American naval presence. Declaring that the United States would formally assume the mantle of “Guardian of the Hormuz Strait,” Mr. Trump stated that Washington would impose a 20 percent fee on all commercial cargo transiting the passage.
According to the president, the revenue generated from the transit fee will directly fund the security operations necessary to keep the global supply lines flowing. “The process and formation will begin immediately,” the president stated, though he did not provide immediate operational details on how the U.S. Navy intends to collect fees from foreign-flagged commercial vessels or enforce compliance without sparking wider international legal disputes.
The immediate reaction from shipping industry groups and international legal scholars was one of profound skepticism.
The United Nations Convention on the Law of the Sea (UNCLOS) guarantees the right of “transit passage” through international straits, a legal principle that traditionally forbids coastal or international powers from levying tolls or arbitrary blockades on commercial shipping during peacetime.
The Strait of Hormuz is widely considered the world’s most important oil transit chokepoint. A narrow waterway separating Iran from Oman and the United Arab Emirates, it connects the petroleum-rich Persian Gulf with the Gulf of Oman and the Arabian Sea. At its narrowest point, the shipping lanes are only two miles wide in either direction.
According to data from the U.S. Energy Information Administration (EIA), roughly one-fifth of the world’s liquid petroleum consumption passes through the strait daily, making it a permanent focal point of global economic stability. Major oil exporters like Saudi Arabia, Iraq, Kuwait, and the United Arab Emirates rely heavily on the passage to move their crude to markets in Asia, Europe, and North America.
For decades, the threat of closing or disrupting the strait has been Tehran’s ultimate geopolitical lever. In times of heightened tension with the West, Iran’s Islamic Revolutionary Guard Corps (IRGC) has routinely conducted aggressive naval drills, harassed commercial tankers, and threatened to shut down the corridor entirely.
By framing this new policy as a selective blockade that isolates only Iranian assets, the Trump administration appears to be attempting to flip the script—disrupting Iran’s remaining illicit oil exports while shielding the broader global energy supply from a catastrophic price spike.
However, maritime experts warn that enforcing a partial blockade on “Iran’s ships or customers” carries immense risk. In practice, much of Iran’s oil is transported via a “shadow fleet” of tankers utilizing flags of convenience, falsified transponder data, and complex ship-to-ship transfers to evade detection.
Identifying and stopping these specific vessels without entangling neutral ships remains an immense operational challenge for the U.S. Fifth Fleet, based nearby in Bahrain.
National security officials in Washington declined to comment immediately on the specific rules of engagement for American sailors executing the order, or how the administration plans to respond if Iran retaliates with its formidable arsenal of anti-ship missiles, naval mines, and drone swarms.