US CENTCOM Enforces Blockade of All Iranian Ports from April 13

US Central Command began enforcing a naval blockade of all maritime traffic entering and exiting Iranian ports today, April 13, at 10 a.m. Eastern Time — the most significant escalation in the 44-day Gulf crisis since the original US-Israel strikes on Iran on February 28. The blockade applies impartially to vessels of all nations calling at Iranian ports and coastal areas on the Gulf and Gulf of Oman, CENTCOM confirmed in a formal statement. Crucially, CENTCOM specified that its forces will not impede freedom of navigation for vessels transiting the Strait of Hormuz to and from non-Iranian ports — a distinction that narrows the blockade’s legal and operational scope from what President Trump had initially posted on Truth Social, where he described blockading any ship transiting the strait.

The blockade announcement followed the collapse late Sunday of the highest-level US-Iran diplomatic meeting since 1979 — 21 hours of negotiations in Islamabad, Pakistan, that ended without agreement after Iran refused Washington’s core demand for a full halt to uranium enrichment. Vice President JD Vance, who led the US delegation, said Iran ‘chose not to accept our terms.’ Pakistani Foreign Minister Ishaq Dar said Pakistan would attempt to restart dialogue in the coming days.

What the Blockade Means for Shipping

The CENTCOM blockade creates an entirely new legal and operational environment for commercial shipping in the Gulf. Vessels bound for non-Iranian ports — including Dubai’s Jebel Ali, Qatar’s Ras Laffan (now restored to daytime traffic), Kuwait’s Mina Al-Ahmadi, and Saudi Arabian terminals — are not covered by the blockade and can transit the Strait under US naval protection if CENTCOM’s formulation holds. However, ships calling at Bandar Abbas, Kharg Island, and other Iranian port facilities are now subject to US interception.

The practical consequences for India are immediate and significant. Iranian tankers carrying crude to Reliance’s Sikka refinery — for which India’s shipping ministry had granted a special one-time berthing exemption just days ago — now face US naval interdiction if they call at Indian ports after having loaded from Iranian facilities. The April 19 expiry of the US sanctions waiver on Iranian oil transactions creates a compressing timeline: India faces both the end of the sanctions window and the new port blockade simultaneously.

Oil Markets React: Brent Jumps 7%, Crude at $104

Global oil markets moved sharply on the blockade announcement. US crude jumped 8 per cent to USD 104.24 per barrel, while Brent crude rose 7 per cent to USD 102.29 — crossing the USD 100 threshold that had been approached but not definitively breached in recent sessions. The price spike reflects the market’s assessment that the blockade, combined with the talk’s collapse and CENTCOM’s mine-clearing operations already underway in the Strait, constitutes a sustained escalation rather than a temporary pressure tactic. Tanker tracking data shows at least two VLCCs making U-turns near Iran’s Larak Island on news of the blockade, highlighting the immediate operational paralysis that CENTCOM’s announcement has created for vessels already en route to or from Iranian terminals.