Iran cannot lose, it just has to survive.
It is not about massive weapons or full scale war. USA can use all the weapons they want, but Iran only need 1 Drone. One strike on a cargo ship in the Strait of Hormuz, and suddenly the risk becomes too high. Shipping slows, insurance spikes, routes get avoided and that ripple travels fast around the world. It can destroy the world's economy. Insurance companies would never insure these ships.
And it doesn't stay as some distant geopolitical issue. It lands right at people's doorsteps. Fuel prices creeping up, food getting more expensive, businesses struggling. It's everyday life that feels it first.
That's why it's so unsettling to watch things escalate. With Israel continuing to bomb Lebanon, and the Strait of Hormuz remaining shut - how long would it actually be before the world starts running short of oil? 1 month? 2 months? It's not going to be far off that!
There's a reason no US president was stupid enough to create conflict with Iran.