states make a solemn but usually unwritten covenant there to send them into battle and risk their lives but only when the vital interests of the or nationals are at stake
States make a solemn, but usually unwritten, covenant with their troops to send them into battle and risk their lives, but only when the vital interests of the nation or nationals are at stake.
States make a solemn, but usually unwritten, covenant their to send them into battle and risk their lives, but only when the vital interests of the or nationals are at stake.