No it won't, that's merely fantasy projection (a personal desire for the US to suffer for what it's doing). US hegemony ended with the rise of China's economy into superpower status over the past 10-15 years. There was no scenario where the relatively brief US hegemony from the late 1980s to the late 2000s was going to continue no matter what the US did. China was always going to build a military to match its economic might. That military will gradually project globally.
US hegemony lasted for a mere ~20 years. Today it does not possess hegemony, China is able to stand-off fully with the US both economically and militarily (at least in Asia).
Iran is a regional conflict. It will matter less than the Iraq war and occupation did.
Nonsense. China remains unable to project power much beyond the first island chain. They're building fast and that will change in a few years but as of today their conventional military capabilities remain very limited and defensive. When was the last time a Chinese carrier strike group deployed to the Middle East?
Maybe. But the Iran conflict also ties in with the Ukraine war, which is an assertion of Russian power into that US-Europe/China duopoly. And it's happening at the same time as the former alliance is breaking.
It's possible that it will be a regional conflict the way the Serbian/Austro-Hungarian conflict was regional. Or the way people pretended that the Germany/Sudetenland conflict was regional.
I don't wish to catastophize. But I also think it's important to realize that this does have the potential to become much worse very suddenly. That doesn't make the decisions easy, but they shouldn't be easy.