The strong people - The reference here is not probably to the Babylonians, but to the surrounding nations. The deliverance of the Jews, and the destruction of Babylon, would be such striking events that they would lead the surrounding nations to acknowledge that it was the hand of God.
The city of the terrible nations - The word ‘city’ here is taken probably in a collective sense, to denote the cities or the strong places of the surrounding nations which would be brought thus to tremble before God. The destruction of a city so proud and wicked as Babylon would alarm them, and would lead them to fear that they might share the same fate, especially as many of them had been associated in oppressing the now delivered people of the land of Judea.