expression, noun which may take the genitive case particle 'no'
under the ... administration; within the ... government
Used with a specific administration or government name, often in the pattern 〜政権下で. Functions as a noun-like expression that can modify other nouns with の.
彼はトランプ政権下で国務長官を務めた。
He served as Secretary of State under the Trump administration.
その政策は安倍政権下で導入された。
The policy was introduced under the Abe administration.