The past two weeks have seen the largest number of attacks against shipping in the Strait of Hormuz since the war between Israel, the United States, and Iran opened on February 28.

President Donald Trump assumed that the conflict would be short-lived, like the strikes against Iran in July 2025 or the campaign against Venezuela.

However, Iran quickly realised that the one method they had available to strike at the United States was right in front of them: global shipping. Using the same tactics as the Houthis in the Red Sea over the previous few years, the Iranians employed uncrewed aerial and surface drones, cruise and ballistic missiles. In a departure from the Houthis, they also laid mines.

Pre-war crude oil shipments were approximately 20 million barrels per day, but that number immediately cratered with the start of the war. Pipelines across the United Arab Emirates and Saudi Arabia provided an outlet for five to six million barrels of oil per day, but the Strait was essential to restore shipments. The closing of the Strait for several months resulted in two billion barrels of oil remaining locked up in the Persian Gulf, causing afloat and ashore reserves to plummet.

In March, the United States called up reservists from the Strategic Sealift Officers programme.

These are licensed merchant mariners who are also officers in the US navy reserve. These officers organised convoys through the Strait and coordinated with the US military for aerial escorts. They provided secure communication with the ships as they transited the Strait. By May, the amount of oil coming out of the Strait began to climb and while it has not returned to pre-war levels, it is fluctuating between the 50 to 75 per cent level.

The new methods being used to ship out oil through the Strait of Hormuz fall into two categories.

First, the large Gulf-state shipping firms, such as Saudi Arabia’s Bari, the Emirates’ ADNOC, and Kuwait’s KOTC have established a shuttle service between the Persian Gulf and the Gulf of Oman. As these ships are partially owned by the states, they underwrote the war risk insurance, and the governments could also provide both military and economic security for the transits.

These ships load in the Persian Gulf and then run the Strait in coordination with the United States Central Command. Typically at night, with no radio, and only limited electronic emissions, the ships hug the southern coast of the Strait and then meet up with empty tankers in the Gulf of Oman. There they conduct ship-to-ship transfers, offloading their cargo to the waiting empty vessels. The process takes approximately five days, and once completed, they make the return run to the Persian Gulf.

The second group of ships comes from the large tanker firms, such as Dynacom and Sinokor, who are getting obscenely high rates to risk their vessels in the region. The current charter rate for a two-million-barrel Very Large Crude Carrier (VLCC, the industry term for a supertanker) to Asia is $1.4m a day. A trip of 21 days equates to $30m.

This rate offsets the higher war risk and the added costs for the crews. The mariners on board are receiving, in addition to danger pay – which typically doubles their salary while sailing in a war zone – bonuses of three months’ pay to make these trips. This cost is adding up to $30 to a barrel of oil. In effect, capitalism has forced the Strait open despite all the Iranians can do.

Since the end of September, the Iranians have escalated the scope and scale of their attacks against shipping, with near-daily strikes taking place. According to the Joint Maritime Information Center, the US is facilitating the passage of 15 ships into the Persian Gulf daily and a like amount outbound. The current level of attacks by the Iranians is hitting approximately 5 per cent of the ships. Some strikes have disabled ships and killed and wounded mariners, but this is by no means always the case.

Some commentators would have it that the return to near pre-war-level exports may indicate victory for the United States, but the truth is different. Yes, the US blockade against Iran since June has effectively cut off Iran’s ability to export oil and not one barrel has left the region on a tanker from Iran. But at the same time, while crude oil is moving, other vital commodities – liquefied gas, ammonia, sulphur, and fertiliser – remain trapped in the Gulf. The oil that is getting out is not sufficient to correct the two-billion-barrel deficiency in the global market and a shortage in refined petroleum products, particularly diesel, is negatively impacting global energy and economic markets.

The United States and Iran remain on a collision course and neither seems prepared to alter their heading. Both are determined to achieve victory, and the Strait of Hormuz is their chosen battleground as the world suffers the consequences of waging a modern-day Tanker War. At the same time, disruptions in energy shipments from Russia are magnifying the issue and any further disturbance – geopolitical or natural – could have an oversized impact on a shipping and energy system that has no margin left.

The quick victory envisioned by the United States and Israel is not happening and instead we are seeing an attritional level of warfare taking place in the Strait of Hormuz similar to the one being waged by Russia and Ukraine on the Black Sea. With the Houthis targeting Saudi ships in the Red Sea, freedom of the seas – a central tenet of the post-World War order – is seriously threatened for the first time in nearly a century.