noun
conscientious objection
Refers to the refusal to perform military service on moral or religious grounds. A formal, legal term.
彼は良心的兵役拒否を理由に兵役を免除された。
He was exempted from military service on the grounds of conscientious objection.
Compound of 良心的 (conscientious) + 兵役 (military service) + 拒否 (refusal).