The physical infrastructure is still there but power projection capacity has clearly retracted a lot, a few years ago I would have said this was entirely due to lack of willpower but I'm thinking something a lot deeper has to be badly broken.
Maybe I'm reading too much into this, but it sounds like Iran might retaliate for the embassy and is making it widely known, and the US is signalling it would stay neutral as long as appearances were kept up.
Not an embassy. Iran has made it clear that should the US push too far their plan is to start blowing up the hundreds of billions of dollars of US industrial infrastructure (oil, refineries, docks, etc) in the Gulf region and North Africa. Most of those state oil companies have their infrastructure owned and operated by US companies like Exxon who then cut them a percentage of the profits.
In a now famous interview with the Iraqi leader, U.S. Ambassador April Glaspie told Saddam, '[W]e have no opinion on the Arab-Arab conflicts, like your border disagreement with Kuwait. ' The U.S. State Department had earlier told Saddam that Washington had 'no special defense or security commitments to Kuwait.