At the time Nahum prophesies, no one would ever think that Nineveh would fall. But this is exactly the message of Nahum. It is not Nineveh, or any great city, that rules heaven and earth, but God. This means two things: (1) Those who continue in wickedness will be judged by God and fall. (2) Yet at His essence, God is merciful and loving, and a fortress to even the weak who trust in Him.