If reports are to believed, big IF, then Iran is now one of the big four, and the big three of US, China and Russia have a new member. Iran has defeated the United States.
For a ceasefire to be called, Iran had ten key demands, and Donald Trump announced he's accepted all of them. This leaves Iran in complete control of the Strait of Hormuz, the Persian Gulf is now its lake.
The US defeat in Afghanistan was the biggest defeat of a western country in history, ancient or modern. Now, this surpasses that. But then, the ceasefire may end within 24 hours, who knows? One thing is for certain, countries are going to find it hard still as the oil isn't flowing yet, and it may take a year or two for flows to resume even if the will exists to make it so.
Update: thinking about this some more, this appears to be Iran's Battle of Britain moment. I'll explain, the BoB was a defensive action, with Britain's goal of avoiding outright defeat. The way the Germans saw it, they were simply trying to knock Britain out, then when they'd done that they turned around to deal with the bigger threat, Russia (then known as the USSR). Thus, Britain claims victory as they were still standing when the attacker quit. Germany, however, say they did not lose, they just changed priorities.
The reality was that Germany was losing aircraft at a rate where they could not replace them. Most losses were on the ground in takeoff and landing, in fact, not fighting in the air. If Germany had continued, they'd have simply run out of planes, while Britain's industry could replace theirs. The Germans badly underestimated the output of the British Midlands.
This appears to be a similar situation in the Gulf. The US lost 11 or so aircraft just rescuing one downed airman, and their bases have all been destroyed in the region. Their carrier strike group has had to retreat well into the Arabian Sea, well away from cruise missiles. Scuttlebutt says that Trump did launch an attack on Iran, in line with his ultimatum, but that every tomahawk cruise missile was taken out by Iran. He buckled after that, and I'm speculating he was told that the US was fast depleting its ordnance and that it couldn't be easily replaced.
Israel has announced they do not consider their offensive in Lebanon as being covered by the ceasefire, and the Gulf states will be unhappy ending up effectively satraps of the new Iranian empire. Therefore, this ceasefire is unlikely to last any more than a few hours or days - we'll see.
And think, we have a Soccer World Cup coming up, that will be interesting.