Over the course of a month, black gold has risen by about 25%. The reason is a new round of escalation between the United States and Iran. Iran claimed it had attacked ten vessels near the Strait of Hormuz after the U.S. sank five Iranian tankers. Through the strategic waterway, which previously handled about 8–9 million barrels of oil per day, now fewer than 2 million pass through.

Against this backdrop, the dollar strengthened to two‑week highs, and the yield on U.S. 10‑year bonds spiked to levels not seen in almost three years. The oil shock has returned — and it is once again changing the rules of the currency market.

The Strait of Hormuz: the largest disruption since the war began

The escalation between the United States and Iran in early September pushed oil prices to new heights. Iran claimed it had attacked ten vessels near the Strait of Hormuz after the U.S. sank five Iranian tankers. U.S. President Donald Trump posted on social media a video created by artificial intelligence in which the Iranian island of Khark — a key hub of Iran's oil exports — was depicted as being “shattered into pieces.” Iranian authorities warned that a strike on Khark would be met with a hard response.

The result did not take long to materialize. Brent crude on September 11 rose above $100 per barrel for the first time since the end of July.

A rise in oil prices above $100 is a direct blow to inflation expectations. And high inflation is an argument for the Fed to maintain a tight policy. The longer oil remains expensive, the greater the likelihood that the Fed will continue tightening, and the stronger the dollar.

As Reuters notes, “fears of further disruptions to energy supplies have pushed oil prices higher.” This, in turn, accelerates inflation expectations and gives the Fed arguments to keep a tight stance.

Meanwhile, Europe suffers from the oil shock more than the United States. Europe imports most of its energy, and expensive oil becomes a serious blow to its economy. This puts additional pressure on the euro and supports the dollar.

What’s next: Brent could settle above $100.

The situation in the Strait of Hormuz remains extremely tense. Analysts warn that if tanker volumes continue to fall, the market could face not just a risk of disruptions but a real shortage of oil supply.

For the dollar, this means continued support. While the Middle East remains in turmoil and oil stays expensive, investors will buy the U.S. currency as the primary safe haven. If oil stays above $100, the dollar could gain a new boost toward strengthening.

One thing is certain: the 2026 Hormuz crisis is only beginning, and its effects on the currency market will be felt for a long time. The old rule that any war automatically strengthened the dollar no longer applies — but the oil shock restores the dollar's role as the world's primary safe haven.