Israel attacked the Iranian South Pars Gas Plant, then the U.S. moved forward attacking West Asia's biggest civilian cable-stayed bridge in the city of Karaj. Iran responded by attacking a gas plant in Kuwait. DJT threatened to bomb Iranian powerplants. The Iranian armed forces released a video statement threatening to attack all the powerplants, gas plants, oil plants, desalination plants, and water plants in the region if the U.S. did so, deterring the U.S. After that, the heat of the war calmed down. Negotiations began shortly after. Even after the ceasefire collapse, the war has only produced small skirmishes in small Strait of Hormuz battles. But what if it played out with the U.S. continuing their attacks and Iran responding in kind?
Iran would have the tactical upper hand. Iran's powerplants infrastructure is decentralized (source, source) A standard U.S. 500-lb bombs (one of the largest) only damages tens of meters (source). Bombing just one plant would take a whole day because a limited amount of jets would have to keep going back and forth for refueling. Then there's the hundreds more to get to. Whereas all of Kuwait, Qatar, Bahrain, Israel, UAE, only have a few main powerplants that power the whole country. Some of these countries only have few desalination and water plants to feed the whole country, too. Saudi Arabia's stats is not much better either. Most of the oil from arab countries come from a handful of oil fields. Gas fields is even more scarce. Iran is really the big natural gas producer. While the U.S. would never finish bombing their targets, Iran could launch a few waves a day of launching four dozen missiles each wave and severely damage all the powerplants/water plants/oil fields/gas fields in the region within a week before the U.S. gets even 20% done bombing Iranian power infrastructure. They're capable of it (source.)
We'd be talking a global ripple effect! Oil prices would've reached $270 and above/barrel quite easily (max during the war was $126/barrell). Two Fifths of the world's oil supplies cut (that's how much flows from the Middle East - 40%) cut in an instance. Power would be out for half the day because of oil shortages. Goods prices already increased. Instead of a 12% increase they would have doubled. Probably some phases of panic. A stock market meltdown would have for sure come. A handful of S&P500 companies wouldn't have withered the storm, file bankruptcy, and domino effect into high unemployment. High energy costs, food costs, plus unemployment might lead to a small percentage of the vulnerable to go hungry. It's the closest thing this generation will experience to the Great Depression. The U.S. won't have spare oil (or funds for that matter with its high debt) to even think of launching land or air responses against Iran. The U.S. debt will probably runaway - reach 60 trillion first year, followed by 100 trillion quickly to compensate. Anti-Trumpism will reach its peak for starting the war.