I may be reading it wrong but without more specific clarity on the way its described, on the Sky Team entry FAQ and lounge finder pages, but I don't see anything in benefits afforded a STE+ member that restrict any lounge entry if flying with any Sky Team member airline to a Sky Team lounge, when on an international itinerary (as they deem international to be.) Certainly nothing that implies or directly states Delta STE+ passengers will be denied entry to Deltas lounges.

At any airport where Delta operate a Sky Club, using the Sky Team website to determine access rules and options, the Sky Club location(s) appear as permitted lounges for First or Business class passengers on an International member airline itinerary to enter, or, those who are on an International itinerary and who hold STE+ status.

E.g.:the following appears for both the LAX T2 and T3 Sky Clubs that Delta operate, on the Sky Team lounge finder website. No reference whatsoever to Delta being permitted to deny entry to any STE+ passenger, or one in First or Business class when on an international itinerary. So it seems somewhere along the line, they've decided or been permitted to diminish to a select group of STE+ passengers the value that the program is supposed to universally deliver.

Lounge access for international First or Business Class ticket holders or SkyTeam Elite Plus Frequent Flyers traveling on an international flight operated by the following airlines:AeroméxicoAir FranceChina AirlinesDelta Air LinesKLM Royal Dutch Airlines

I get that a passenger in the above case could head to TBIT and access KE instead but that requires some amount of foot travel and again, my beef is that it seems an arbitrary rule that Delta are imposing.

Are any other ST carriers also restricting access to their own elites in this way?