のもとで・
This construction presents an action or state as taking place under someone’s authority, within a governing system or condition, or with the support or influence of something.
The relationship it expresses
The noun before the construction must genuinely frame what follows. A supervisor can direct an activity; a law or policy can govern it; cooperation can support it; and pressure or difficult conditions can influence it. English “under” often works, but the important point is this governing, supportive, or influential relationship.
Authority, principles, and conditions
田中教授の指導のもとで、若手研究者たちは新しい治療法を調べている。
Under Professor Tanaka’s guidance, the young researchers are investigating a new treatment.
Analyze全員参加という方針のもとに、新しい委員会が設置された。
A new committee was established under a policy of participation by everyone.
Analyze厳しい安全基準のもとで、実験が行われた。
The experiment was conducted under strict safety standards.
AnalyzeA governing framework versus a general setting
のもとで says that rules, authority, support, or conditions govern the event. By contrast, において formally identifies the place, occasion, or field where something happens without adding that relationship.
More examples
新しい校長のもとで、学校改革が進んでいる。
School reforms are moving forward under the new principal.
Analyze政府の支援のもとで、被災地の住宅再建が始まった。
Housing reconstruction in the disaster-stricken area began with government support.
Analyze双方の合意のもとに、調査委員会が設置された。
An investigative committee was established by mutual agreement.
Analyze強い世論の圧力のもとで、政府は方針の見直しを決めた。
Under intense public pressure, the government decided to review its policy.
Analyze共通の理念のもとに、五つの団体が一つの連盟を設立した。
Five organizations founded a single federation around a shared philosophy.
Analyze新しい教育方針のもとで、授業内容が全面的に見直された。
Under the new education policy, the course content was completely revised.
Analyze