Understanding the escalation of violence between Iran and the United States since 2018, in six points

Tension between Washington and Tehran has steadily increased since the US pulled out of the Vienna Iran nuclear deal and restored economic sanctions. Over the months, their diplomatic and economic tug-of-war has evolved into increasingly violent episodes, until the assassination, ordered by Donald Trump, of the head of the Iranian Revolutionary Guard's special forces, Ghassem Soleimani , Thursday January 2. Back on a year and a half of climbing.

1. The United States withdrew from the agreement

While his predecessor, Barack Obama, had done everything to improve relations between Washington and Tehran, Donald Trump withdrew the United States from the Vienna agreement on Iranian nuclear power on May 8, 2018. This compromise, hardly signed three years earlier by Iran, Russia, China, France, Germany and the United Kingdom, aimed to limit Tehran's nuclear program, when they suspected of wanting to develop the atomic bomb, in exchange for the lifting of economic sanctions. Made possible by the arrival of a moderate president in Iran, Hassan Rohani, the deal was respected by Tehran, according to the International Atomic Energy Agency (IAEA).

2. Economic sanctions strike Iran

Despite regular and positive reports from the nuclear gendarme, Donald Trump has reinstated heavy economic sanctions against Iran. After a transitional period of ninety days after the withdrawal of the agreement, a first phase of economic sanctions fell, in August 2018, on the banking, raw materials, automotive and civil aeronautics. In November of the same year, they expanded to the oil and gas sector and the Iranian central bank. The value of the rial, the national currency, has been divided by three or even four in a few months. The outstretched hands of Europeans, anxious to keep the deal, failed to make up for the country's dismay on the brink of suffocation.

3. Iran violates the Vienna agreement

Cornered, Iran has announced that it will no longer respect the Vienna agreement. The country is gradually starting to no longer comply with the provisions of the agreement – without however officially denouncing it. A month after the withdrawal from the United States, Tehran first announced its plan to increase the number of its centrifuges – allowing it to increase its stock of enriched uranium. In July 2019, the Iranian authorities announced that they would resume uranium enrichment beyond the authorized rate of 3.67% – up to 4.5%, a level however far from the 90% necessary to consider the manufacture of an atomic bomb.

Then, they recognized that their stock of low enriched uranium exceeded the authorized 300 kg. These minor, but repeated violations of the agreement are not analyzed by experts as a real resumption of a military nuclear program, but as a "Call for help to its partners".

4. Oil, at the heart of the economic war

In order to survive economically, Iran has also undertaken to circumvent the blockade imposed by Washington on its oil exports – sanctions further tightened in May 2019 by Donald Trump. Iranian carriers have registered their ships abroad, and as of October 2018, its tankers cut off their GPS beacons to mask their movements.

Then the incidents of oil tankers multiplied. In June, two Norwegian and Japanese ships were the target of an indefinite attack that the United States blamed on Iran. British authorities seized Iranian oil tanker in early July Grace 1 off Gibraltar, accused of wanting to deliver Syria, subject to an embargo. In response, the Islamic Revolutionary Guards arrested a Swedish tanker and then seized a ship under the British flag.

5. Summer 2019: the drone war

During the summer, the climate became tense in the sea, but also in the air. On June 20, Iranian authorities shot down an American drone that they claimed was violating their airspace. In reprisal, the American president ordered targeted shots, before changing his mind "Ten minutes before the strike". A month later, the United States said it had shot down an Iranian drone that had come too close to an American ship in the Strait of Hormuz, while Tehran claimed that all of its drones had returned.

Tension increased a notch in mid-September following the attack on two Saudi oil infrastructure, the Abqaïq plant and the Khouraïs field. The production capacity of Aramco, the company of the Saudi kingdom, an ally of the United States, had been halved due to this event. The United States quickly accused Tehran, followed a few days later by Paris, Berlin and London.

6. Air strikes

After this attack, the violent events accelerated. In November, Israel bombed Iranian sites in Syria. Then, at the end of December, the United States launched air raids, killing 25 people from the pro-Iranian Hezbollah movement in Iraq and Syria. Two days later, thousands of supporters of Hachd Al-Chaabi, a coalition of pro-Iranian Shiite militias, forced the entry of the American embassy into Iraq. Until January 2, when Donald Trump ordered the strike that claimed the lives of Al-Quds Force chief Ghassem Soleimani, further heightening fears that this escalation would turn into direct military confrontation between the two enemy countries.