It would be the same as any modern prophet shaking his finger at some dominant superpower, warning their doom was close. It all seems too far beyond the pale, to unlikely. Could there be a god capable of destroying such monumental power? So Nahum rubs it in, conjuring the most shocking images of destruction.
Predation was their god, and the world knew the Ninevites could not be trusted to keep any promises or treaties. God hates broken treaties. When the Ninevites got bored, which came pretty easily, they would start a new war with their closest allies just to have an enemy to attack. They were bursting with plunder, but this made them a target.
Were you a mere bystander watching, perhaps the great tumult of chariots and warriors, both inside and outside the city, would be high entertainment. But only a Ninevite could truly appreciate the unspeakable slaughter which was waiting them. In classical Hebrew poetry, Nahum describes a scene of stumbling over dead bodies, the stench and disease so hard to escape because the destruction was beyond description.
The prophet compares the city to a prostitute, but this one always inflicted crippling wounds to all her lovers, forcing them into lifelong dependence on her. It required the most obscene sorcery, calling up the powers of Hell to blind men so. To a Hebrew reader, it’s hard to imagine more evil rolled into a single image. What we also find hard to understand is the huge difference between the nudity of intimate privacy versus the hideous exposure of public nakedness. The Lord promised to expose Nineveh, humiliating her in the light of the sun, exposing her as an old hag with the makeup caked on and her gaunt shape exposed from under those colorful enticing sheer skirts with hidden padding. No one dares to weep for such a sight.
The ancient Theban capital of Egypt was so very secure, but Nineveh had no trouble crossing the open water to bring her down. Did she then think herself any more secure than Thebes? All the horrors wrought on Thebes would be worse, if possible, for Nineveh. Tough, predatory and violent? Wait until she was taken down by those she thought she ruled, Babylon and Persia. Her own defenders, so numerous as locusts swarms, would be like old locusts devoured by yet another fresh generation of an even larger swarm. What you are, you will beget as worse yet.
So the Lord would scatter these warrior peoples, drive them back into their ancient mountain villages to the north of the plains, never again to assemble as a single nation to conquer. No one would remember proudly any association with them, but would cheer, and laugh over her demise. No one will miss her, will reminisce fondly over her greatness. It’s time to party hearty, because Assyria is broken!