Iran Halts Strait of Hormuz Shipping Again After Israeli Strikes on Lebanon, Over 400 Tankers Stranded as Oil Prices Reverse on April 9

The fragile US-Iran ceasefire, announced late Wednesday by President Donald Trump, collapsed within 24 hours as Iran's Islamic Revolutionary Guard Corps (IRGC) reimposed a blockade on the Strait of Hormuz on Thursday morning following fresh Israeli airstrikes on Lebanon. Oil markets reversed course on April 9, with Brent crude recovering toward the $97-$98 range and WTI climbing back above $96 per barrel, partially unwinding Wednesday's historic 15-percent plunge.

Over 400 Tankers Remain Stranded in the Persian Gulf

As of Thursday morning local time, MarineTraffic vessel tracking data showed more than 400 crude oil tankers, 34 liquefied petroleum gas (LPG) carriers, and 19 LNG vessels anchored or drifting in wait-areas just east of the Strait, unable to transit toward Indian Ocean shipping lanes. The vessel backlog represents multiple days of disrupted flows through a waterway that handles roughly 20 percent of global oil and gas supply each day.

Iran's IRGC cited Israel's renewed strikes on Hezbollah positions in Lebanon as a violation of the ceasefire framework, triggering the reimposition of Hormuz access controls. Tehran had conditionally agreed under the two-week ceasefire to allow coordinated tanker transits managed through Iran's armed forces. The abrupt reversal, occurring less than one full day after Trump's announcement, has raised serious doubts about whether diplomatic talks can produce a durable arrangement before the 14-day window expires.

Ceasefire Framework: What Collapsed

The ceasefire announced Tuesday evening was structured around Iranian agreement to reopen the Strait temporarily, with Israel also reported to have accepted the arrangement. However, the deal contained no enforcement mechanism to prevent third-party actions that either side might declare a breach. When Israeli forces launched fresh attacks on Lebanon Wednesday night, Tehran's IRGC declared the strikes a material violation and reimposed the blockade by Thursday.

Analysts described the structure as inherently unstable. The arrangement required Israeli restraint as an implicit precondition, yet Israel's objectives in Lebanon were not part of the US-Iran negotiations. Markets had priced in a rapid normalization of Hormuz flows, sending WTI down from as high as $117 per barrel on Tuesday to $94.41 at Wednesday's close, the largest single-day crude price decline since 2020. That relief trade is now partially reversing.

Wednesday's market wrap covered how the initial ceasefire announcement rippled through Canadian crude markets, briefly narrowing Western Canadian Select (WCS) differentials before uncertainty widened spreads again through the evening session.

Brent and WTI Recover as Hormuz Risk Premium Returns

Thursday's partial price recovery reflects the market re-pricing a Hormuz risk premium that was prematurely removed on Wednesday. Brent crude futures climbed back toward $97-$98 per barrel in early April 9 trading, while WTI recovered toward $96-$97. The moves suggest traders are treating the ceasefire as fragile rather than durable, with positioning skewed toward further upside volatility if Hormuz remains closed beyond the weekend.

OPEC and its partner countries collectively announced a 206,000 barrel-per-day production increase for May 2026, but analysts note that additional Gulf state output has limited market impact without safe Hormuz passage to move barrels to buyers. Saudi Aramco exports approximately 7 million barrels per day, nearly all of which transits the Strait. With the blockade renewed, Saudi export revenues remain sharply curtailed regardless of upstream production levels.

Canadian Producers: Trans Mountain as an Alternative Route

For Canadian oil producers, the renewed Hormuz closure reinforces the strategic value of Pacific Coast export infrastructure. Trans Mountain Pipeline hit utilization records in April 2026 as Asian buyers sought alternative delivery routes to Middle Eastern supply disrupted by the Strait closure. Alberta's oil sands producers, including Canadian Natural Resources, Cenovus Energy, Imperial Oil and Suncor Energy, are collectively targeting nearly 3.9 million barrels of oil equivalent per day in 2026, with Trans Mountain providing crucial access to Pacific markets.

The volatile swing between Hormuz open and closed has complicated hedging for Canadian producers. WTI settled near $95 on Wednesday before the Thursday rebound, and the WCS differential has shifted sharply across the same period. Operations teams and trading desks are adjusting export scheduling assumptions daily as the geopolitical situation evolves.

What Traders and Diplomats Are Watching

The next 48-72 hours are widely regarded as the most critical period for both diplomatic progress and oil market direction. Talks convened in Islamabad this week aim to formalize a more durable ceasefire arrangement, including clearer provisions around Israeli actions in Lebanon. Any breakthrough that restores Hormuz tanker transit would send crude prices sharply lower again; a full breakdown of negotiations would likely push Brent back toward the $110-$115 range that prevailed before Wednesday's announcement.

As of Thursday, the Strait remained effectively closed. Each additional day of blockade deepens the logistics burden facing refiners in Europe, India, Japan, South Korea and China. Until tanker traffic resumes at meaningful scale, global energy markets will price crude with a substantial geopolitical risk premium built in.

• WTI (April 9 recovery): Approximately $96-$97 per barrel, up from $94.41 close on April 8
• Brent (April 9 recovery): Approximately $97-$98 per barrel, up from Wednesday's $94.75 settle
• Vessels stranded: 400-plus tankers, 34 LPG carriers, 19 LNG vessels in Persian Gulf anchorages
• Hormuz transit volume affected: Approximately 20 percent of global daily oil and gas supply

Sources: World Oil, CNBC, OilPrice.com, Fox Business