As Samir Madani studies satellite images of Middle East ports and tankers' position data, he often airs the secrets of international oil trading. He noticed on July 19 that the British tanker Mesdar in the Strait of Hormuz had deviated from his course and approached the coast of Iran.

It was not long before the news leaked that the Iranian navy had pushed the tanker away, as had the tanker Stena Imperio. Madani looked in his database for the Mesdar. Madani is the founder of, a web platform that provides information about global tanker traffic. In his search for the Mesdar , he found that the ship has operated several times between the Ras Tanura oil port in Saudi Arabia and China over the past two years. He was sure that the Mesdar would not be confiscated despite the Iranian naval maneuver. "With oil for China on board you will not have any problems with Iran," says Madani.

In the Strait of Hormuz, world politics is condensing in a small space. The Strait between Oman and Iran connects the Persian Gulf with the Indian Ocean, at its narrowest point it is less than 40 kilometers wide. And she has become the scene for the sanctions policy against Iran.

According to the US Energy Information Administration, nearly 21 million barrels of crude oil were transported through the straits every day, accounting for around one fifth of global oil exports. Deliveries come from Iraq, Iran, Kuwait, Bahrain, Qatar, Saudi Arabia and the United Arab Emirates. About three-quarters of the shipments go to Japan, India, Singapore and, above all, China. The Strait of Hormuz is a kind of bottleneck of the petroleum trade. If shipping stops at this point, companies around the world are threatened with problems - and now it's time.

The US is pushing with maximum pressure to force a new agreement with Iran, in which the country declares itself ready to reduce its nuclear program. Therefore, they have tightened the sanctions against the Iranian oil industry.

It's getting tight in the Strait of Hormuz.

© TIME graph

Iran, for its part, is threatening to close the Strait of Hormuz. Since May, six oil tankers have been attacked in the region, the United States make Iran responsible for it. On July 19, then, the Iranian Navy seized the British flagged tanker Stena Imperio. Apparently in retaliation. Shortly before that, the British navy had stopped an Iranian tanker off Gibraltar, allegedly supplying oil to Syria, bypassing the Suez Canal, and sanctioning it.

Apparently this is not an isolated case. At least, market watcher Madani reports on several tankers he discovered on satellite imagery that would help Iran break US sanctions. They load their cargo in Iran, cross the Strait of Hormuz, then drive up the Red Sea to the Suez Canal. Afterwards, they switched off the system for automatic position determination. They can then no longer be tracked electronically. Finally, they reappear on satellite imagery from the Syrian unloading station of Banijas.