Which is working so well against Iran, right?
Oh wait, no, the other thing.
Oh wait, no, the other thing.
They were trying to overthrow the regime, for the second time in a year, and failed.
It actually depends on what the you the outcome of the war to be: total conquest or regime change.
The US can probably achieve total conquest, but not regime change. They spent 20 years in Iraq and Afghanistan and left there without winning anything, especially in Afghanistan. If they wanted to erase Iraq and Afghanistan, that would have a been a totally different thing.
I have to wonder what your definition of "winning" is.
My god man, Vietnam vets are still alive. You can talk with them today. There is no reason to forget all of the lessons of the past.
Since then Iran's economy has been crushed, government was decapitated (and could be again at a time and place of our choosing), they face a naval blockade that prevents them from selling oil, their military was drastically reduced in size and capability by American bombing, they've made their fellow Arabs in the region very, very angry, and they've come to see that both China and Russia (don't forget, Iran sells drones to Russia to kill Ukrainians) were powerless to come to its aid. Their nuclear program is at best on pause.
Now we can sprinkle in that they've depleted a lot of their munitions, and both Hamas and Hezbollah were nearly destroyed and have become shells of their former selves, resorting to hiding behind children and attacking UN aid convoys.
Just in case you thought Iran was somehow coming out of this situation better than before, the above shows that is unequivocally false.
But hey, yea the US "lost the war".
There were no clear objectives when the war started, but the Trump administration has waffled since about:
Regime change - hasn't happened. The current regime is still running the country.
The end of the assumed nuclear program - hasn't happened.
Destruction of Iran's military - hasn't happened. Iran is still sending drone strikes against US bases in neighbouring countries.
and more recently, opening the Hormuz Strait to commercial shipping - hasn't happened.
Not a single identified US objective in the war has been achieved, and the USA has lost massive respect from the rest of the world because it has been unable to achieve any of its objectives against a third-rate country. It has also drained its interceptor reserves in a way that might have material effect on future conflicts (e.g. Taiwan)
As for Iran, it didn't start the war so it doesn't get a checklist of objectives. However:
Iran is selling oil that it was previously unable to because of sanctions. The on-again-off-again US blockade of the strait isn't really affecting this.
The regime has a much tighter grip on power than it had pre-war, there are no mass demonstrations and it is not shooting its own civilians any more
It has confirmed control over the Hormuz strait and looks likely to be able to charge tolls in the future.
It has seen the Middle East pull away from the USA and pull together, a strategic benefit for it.
There is no reading of this war that makes the USA look good here. It was a mistake in the first place and it's been a colossal cock-up ever since.