war preparation; preparations for war
Refers to military buildup, mobilization, or readiness activities before or during a conflict.
That country is proceeding with war preparations.
War preparations require enormous expenses.
軍備 refers more broadly to armaments and military strength, while 戦争準備 emphasizes the active process of getting ready for a specific war.
Compound of 戦争 (war) and 準備 (preparation).