According to the author of 1 Kings, God warns the king of Israel to get ready and be strong because next year the king of Syria will attack again. It's like when someone tells you to prepare for a big test because it will happen soon.
1 Kings 20:22: And the prophet came to the king of Israel, and said unto him, Go, strengthen thyself, and mark, and see what thou doest: for at the return of the year the king of Syria will come up against thee.
This verse suggests that safety and victory in battle ultimately depend on the Lord, which contradicts the pragmatic and strategic military planning advised by the prophet to the king in 1 Kings 20:22.
Proverbs 21:31: The horse [is] prepared against the day of battle: but safety [is] of the LORD. [safety: or, victory]