noun
preventive war
A war initiated to prevent a perceived future threat, often used in political and military contexts.
予防戦争の概念は国際法で議論されている。
The concept of preventive war is debated in international law.
先制攻撃 is a preemptive strike, often a single military action, while 予防戦争 is a full-scale war launched to prevent a future threat.
Compound of 予防 (prevention) and 戦争 (war).