noun
nonaggression pact; nonaggression treaty
A formal agreement between nations to refrain from military aggression against each other.
両国は不侵略条約を結んだ。
The two countries concluded a nonaggression pact.
不可侵条約 is a more common synonym with the same meaning; 不侵略条約 is less frequent but still used in diplomatic contexts.
Compound of 不 (non-), 侵略 (aggression), and 条約 (treaty).