President Donald Trump has threatened to “massively blow up the entirety” of Iran’s South Pars gas field if Tehran launches further attacks on energy facilities across the Gulf.

Israel struck the vital gas field on Wednesday morning in a move that drew condemnation from both Iran and Qatar, a close ally to the US, who share the facility.

In retaliation, Tehran struck multiple energy facilities across the Gulf, including Qatar’s Ras Laffan Industrial City, where an estimated 115,000 people work.

The US president lashed out at Iran over the strike on Ras Laffan in a post on Truth Social, where he claimed that Israel’s strike had only hit a “relatively small section of the whole” facility. He added that Washington knew nothing about the attack.

“Unfortunately, Iran did not know this, or any of the pertinent facts pertaining to the South Pars attack, and unjustifiably and unfairly attacked a portion of Qatar’s LNG Gas facility,” he said. “NO MORE ATTACKS WILL BE MADE BY ISRAEL pertaining to this extremely important and valuable South Pars Field unless Iran unwisely decides to attack” Qatar, he added.

He then warned that if Iran did attack Qatar again, the US would “massively blow up the entirety of the South Pars Gas Field at an amount of strength and power that Iran has never seen or witnessed before.”

Strikes on the South Pars gas field mark a significant escalation in the three-week-old war which could have devastating long-term consequences. Here is why.

Why did Israel target South Pars?

Israel has so far targeted top Iranian officials as part of its war strategy, leading to the deaths of security chief Ali Larijani and Basij paramilitary force commander Gholamreza Soleimani. Alongside this, the IDF has pounded military installations across Iran with bombs.

But experts say the move towards attacking energy infrastructure marks a transformation in Israel’s strategy that could have a significant impact on Iranian civilians and the wider global economy.

Dr Umud Shokri, an energy strategist and senior foreign policy advisor, said that a full strike on South Pars was a “worst case scenario” as it is key to Iran’s energy supply, feeding power generation, heating, industry and petrochemicals.

“Disruption doesn’t just hit exports, it hits daily life. Expect outages, shortage, and inflation almost immediately, meaning ordinary Iranians absorb the shock first,” he wrote on X.

He said that the move would not necessarily have a destabilising impact on the regime, as it could instead offer them a justification to tighten control and blame external forces.

Which energy facilities did Iran threaten in response?

Iran distributed evacuation notices to Saudi Arabia’s Samref Refinery and Jubail Petrochemical Complex, the United Arab Emirates’ Al Hosn Gas Field, and Qatar’s Mesaieed Petrochemical Complex, Mesaieed Holding Company and the Ras Laffan Refinery on Wednesday.

The Ras Laffan Industrial City, where an estimated 115,000 people work, was struck by a ballistic missile on Wednesday sparking a huge blaze, according to the country’s state-owned QatarEnergy company. Four out of five missiles were intercepted by the country’s military.

“Emergency response teams were deployed immediately to contain the resulting fires, as extensive damage has been caused. All personnel have been accounted for and no casualties have been reported,” QatarEnergy wrote in a post on social media.

Why are the attacks important?

South Pars is the world’s largest fossil gas field, shared between Iran and Qatar.

The strikes from Israel mark the first time facilities associated with the production of fossil fuel energy have been hit in the war, as opposed to sites such as ports which are used to transport oil.

The strike could have a years-long impact on the damage to production itself, experts have warned, which could last after the war ends.

Saul Kavonic, an analyst at MST Financial, told the Financial Times: “Something that takes out a few million barrels of production would have a bigger impact because it means there is no way to refill stocks even after the war ends.”

Hitting a liquefied natural gas facility would be the worst, he added, because it could take several years to repair.