It seems Hassan Rohani kept his word. "If one day they want to prevent the export of Iranian oil, then no oil will be exported from the Persian Gulf," promised the President of the Islamic Republic in a TV address last winter with regard to the US economic sanctions.
At the weekend, the world's largest oil refinery in Saudi Arabia was apparently attacked with drones and rockets, oil production had to be massively throttled.
The Sunni Kingdom of Saudi Arabia is the archenemy of the Shi'ite ruling state of Iran. The two countries are waging a shadow war in the Middle East, including in the civil war country of Yemen. There, an alliance led by Saudi Arabia is fighting against the Shiite Houthi rebels, who are being supported by Iran.
Who is behind the attack?
It is true that on Saturday the Houthis were known for attacking the assets of the Saudi Arabian state-owned company Aramco. And from Riyadh it is said that the Houthi rebels used Iranian drones. But whether the Tehran-backed fighters are actually behind the at least 17 impacts, especially many hundreds of miles away from their dominions, is open.
According to The New York Times, US government officials believe that the precise and extensive attacks came from the northern Persian Gulf, and thus Iran or Iraq. But still there is no proof for it.
One thing is for sure: So far, Iran and Saudi Arabia have delivered a remote duel. If Iran were actually behind the attack, that would be a novelty - and the danger of a war between the two states is acute.
What does the attack mean for Crown Prince Mohammed bin Salman?
But one thing is silent so far: Mohammed bin Salman, short MbS. Saudi Arabia's young Crown Prince invests a lot of time and money into his own image-building: he presents himself as a reformer who gives women new rights and leads the country out of dependence on oil.
The murder of journalist and dissident Jamal Kashoggi at the Saudi Arabian consulate in Istanbul a year ago has severely damaged his reputation. MbS is regarded by many as a nefarious ruler who does not shy away from archaic means in the pursuit of critics.
The drone attack on the oil plants is now also a problem for him. MbS, who likes to portray himself as a strong man, suddenly looks like a ruler who is unable to protect his own people. The Crown Prince is now under pressure. It is a stress test: If he does not want to appear weak, he has to react to the attack.
How does US President Donald Trump react?
The US stood "gun at foot". That's what Donald Trump once said after Iranian Revolutionary Guards shot down an unmanned US spy drone in the Gulf in June.
A retaliation Trump blew off at the last minute. The danger of meeting civilians was too great, he claimed. Now he has his threat almost word for word again.
On the one hand, Trump does not want a new war in the Middle East. He promised his constituents to bring foreign soldiers back to the United States. A military confrontation - just over a year before the presidential elections in 2020 - could, he seems to fear, reduce his chances of re-election.
On the other hand, the Iranian-American conflict has already developed its own momentum, which can lead to a sudden escalation at any time. US officials told The Washington Post that the Trump government was discussing a military strike. Trump met with Defense Secretary Mark T. Esper on Sunday.
How does the incident affect possible nuclear negotiations between the US and Iran?
Recently, signs of American-Iranian reliance were on cautious relief: Trump signaled his willingness to meet with his Iranian counterpart Hassan Rohani. US Secretary of State Mike Pompeo reiterated that such a meeting could take place on the sidelines of the UN General Assembly in New York at the end of the month.
There is no talk of that now. Trump claims he has never agreed to negotiations with the Iranian leadership without preconditions, which is proven to be wrong. And also the Iranian regime affirmed on Monday: There will not be a meeting with Trump in New York.
Trump pursues a strategy of "maximum pressure" on Iran. Under him, the United States has withdrawn from the nuclear agreement that its predecessor, Barack Obama, had negotiated with the country. Instead, the regime in Tehran should be held, inter alia, by sanctions from the construction of a nuclear bomb. So far this policy has been unsuccessful.
The departure of US security advisor John Bolton from the government last week raised hopes that the US and Iran could start a new conversation. This hope is gone for now.