Ramstein could be a refuel stop. If not, other possibilities are a Landstuhl Hospital visit (next town over). K-Town, which may be largest US settlement outside of CONUS & territories is a few miles away.

Very secure. I think that if Assange had been exfiltrated and was in need of medical attention he would have been airlifted to Landstuhl.

Have to see, too, if it's actually a visit and not a refueling, if there's a Merkel meeting. I would say pretty big deal, if it's a POTUS visit & no Merkel meeting.

Keep in mind, too, if we look at Q's info that POTUS will be on AF1 and secure abroad, Ramstein would be the place, IMO. Timing warrants a good look.

Of course, most likely just refueling. Ramstein the only game in town anymore for military aircraft AF1 size in Germany, I think.