The Jews who fled to Egypt hoped to find a safe haven, but they are destined to experience the exact same destruction that devastated Jerusalem. This fate stems from their choice to join Pharaoh's army in an attempt to fight against Nebuchadnezzar. Because of this alliance, they are doomed to fall in battle alongside the Egyptian casualties [מלבי״ם].
The impending disaster is not a random tragedy or a natural consequence of war, but rather a deliberate and divinely directed destruction [מלבי״ם]. God declares that He will focus His attention on the exiles with specific intent. He will watch over them individually to ensure they are punished and paid back for their actions [מצודת דוד, מצודת ציון]. This retribution will be carried out through sword, famine, and plague, as these are the precise tools through which God will deliver their punishment and exact payment for their deeds [מצודת דוד].