noun
reciprocal treaty; treaty of reciprocity
A formal term used in diplomacy and international law for a treaty where two or more parties grant each other mutual benefits or rights.
両国は互恵条約を締結し、関税を引き下げた。
The two countries concluded a reciprocal treaty and lowered tariffs.
条約 is a general term for any treaty, while 互恵条約 specifically refers to a treaty based on mutual benefit.
Compound of 互恵 (mutual benefit) and 条約 (treaty). The exact historical derivation is uncertain, but the term is a standard Sino-Japanese compound used in diplomatic contexts.