Oil prices jumped more than 7% when President Trump reimposed a blockade on Iranian ports in July, preventing ships from entering or leaving Iran. It is the third time he has turned this policy on and off since April NBC News.

This back-and-forth matters because oil prices move on uncertainty. When traders think a blockade will last, they buy oil now before prices rise further—that pushes prices up immediately. When they think the blockade will end soon, the rally fades. The pattern since April has been: blockade imposed, oil spikes, a deal gets announced, blockade lifts, tensions return, blockade reimposed. Because this has happened three times in four months, traders no longer trust that any single announcement will last. They now price each blockade as temporary.

The immediate trigger was a July 7 military strike by the US against Iran, which sent oil up 9% that day before Trump said there would be no full-scale war—prices settled at a multi-week high Reuters. Three days later, US officials said they wanted Iran to stop attacks near the Strait of Hormuz, the channel through which about one-third of the world's seaborne oil passes. That demand failed to gain traction, and the blockade was reimposed.

How the Cycle Started

On April 13, Trump announced on Truth Social that the US would blockade Iranian ports, framing it as a temporary measure—in force "until the transaction with Iran is 100% complete." The White House said the blockade was needed to counter Iranian aggression and keep the Strait of Hormuz open White House. By late April, Trump was telling Iran to "just give up," while officials pushed Congress to renew unspecified powers tied to the blockade Al Jazeera. In mid-May, Trump met with oil company executives to discuss extending the blockade for months, suggesting it might be permanent Reuters via X.

Then, without warning, Trump reversed course. He announced the Strait was "OPEN, and will remain OPEN, with or without Iran," but also said he was reinstating "THE IRANIAN BLOCKADE"—confusing posts that happened close together and captured the on-off nature of the policy. By June 19, the White House declared the Iran dispute resolved, saying a deal ensured Tehran would never get a nuclear weapon and reopened the Strait to free passage White House. Trump said the deal was "complete."

Two days later, the Guardian reported Trump facing criticism from both parties over the Iran agreement, with new threats to reimpose the blockade The Guardian. On June 23, Trump announced the US was waiving some Iran sanctions because Tehran had supposedly agreed to let international inspectors into its nuclear sites indefinitely Reuters—a sign diplomacy was still happening, even as blockade threats continued.

The Real Cost Is in Shipping, Not Just Gas Prices

When oil prices jump and fall this quickly, the headline number—"oil up 7%"—hides where actual economic pain shows up. Tanker ship owners and the companies that insure them against war damage face a real problem. If a blockade might come back in six to eight weeks, nobody wants to sign a long-term contract to haul oil through the Strait of Hormuz at today's insurance rates. Insurers can't change their prices as fast as Trump changes policy on social media.

This is why traders watching the shipping and insurance markets are more nervous than the oil futures markets suggest. If traders genuinely believed the blockade might stick this time, the cost to insure a tanker through Hormuz would be much higher, and long-term oil prices would be higher than near-term ones. Right now they are not.

The confusion runs deeper because different Trump policies are moving on different schedules. A February executive order imposed financial sanctions on Iran over human rights concerns White House. That is separate from the blockade. Sanctions relief, blockade orders, and Strait-reopening declarations have all changed on overlapping but different timelines, making it nearly impossible for markets to price a single "Iran risk." Instead, traders are tracking five different policy tools that move independently.

Based on what has happened—three times announcing the blockade would end, three times reimposing it—anyone betting on what comes next should assume neither permanence nor a long time frame. The base case is reversibility. Expect changes.