> Military power projection is the reason the US was able to destroy a significant portion of Iranian leadership, nuclear infrastructure, and weapons infrastructure with no retaliation from Iran back in the US nor any pushback from any of Irans allies.

First, Iran doesn't have allies, it has friends of convenience (Russia like the military cooperation but don't like the cheap oil competition, China love the cheap oil competition but don't care for the damage, etc).

Second, US bases and US allies (in the actual sense of the word) were attacked by Iran, successfully. US and all its allies were also impacted by the trivial closure of the Hormuz. US allies now will forever know that the US is not a reliable ally and can't protect them; stocks of crucial materiel were wasted on achieving nothing; and high oil prices will cost the US domestic politics dearly. US power projection whacked a few nutjobs from a regime full of them. Oh, and they're a theocracy that believes in martyrdom! And the new supreme leader is a strong proponent of nuclear weapons (unlike his predecessor and father), and saw half his family blown up in front of him.

> Military hegemony has nothing to do with being a perfect police force that can stop anything from happening anywhere.

Being unable to enforce your will on an enemy is not "hegemony". Iran will walk out of this conflict with their nuclear programme back on track, a revenge minded regime, and maybe even a toll on an international strait to fill up their coffers.