if all of irans neighbours deny us air assets the use of their air fields then the us capability to strike at iran is greatly reduced. with irans pretty beefy air defenses and its strategic partnership with russia and china it was questionable how effective a us bombing campaign would have been with the use of the air fields in the region. without those air fields? iran is going to be a lot tougher. insurmountable to the us military. probably not. but the us military needs to keep large reserves to check us competitors from making power grabs.  without clear air superiority a war with iran would take a heavy toll on the us military. with how strained internal relations are in pretty much every single western country, it is not at all certain that the american people will accept the losses necessary to defeat iran militarily. especially now that drones have blunted the striking force of armored vehicles, the us military might need to resort to russian style tactics to advance. that is something the us military and the citizens are not used to, the involved losses would most likely send shockwaves through american society. the us empire is coming to a point where it needs allies to achieve any of its goals and where its competitors are bridging the gap in power.  the next war of the us will not be iraq or afghanistan where the us held overwhelming firepower. it will be korea, where tens of thousands of men died.
Germany