Solution: Diplomatic office below an embassy - NYT Crossword

From libation to LEGATION, a new term to me. In 1952, this entry was clued as “Perle Mesta’s headquarters in Luxemburg [sic], for instance.” Back then, the United States had embassies in prime locations and LEGATIONS in smaller countries, staffed by lower-level ministers rather than ambassadors. Since then, though, everything’s gotten upgraded and homogenized, and there aren’t any American legations to speak of — there are embassies everywhere. The legation in Tangier, Morocco, has been preserved, however, and is the only U.S. National Historic Landmark located outside the U.S.