In a moment of painful clarity, the people recognize the illusion of depending on foreign empires. The ultimate realization is that Egypt can never serve as a reliable source of security [שד״ל]. The inhabitants of the land of Israel and Judah are described as living on an island, a concept understood in several ways. Geographically, the land borders the sea [רד״ק, מצודת דוד]. In a broader sense, the term can simply denote a specific region or territory, even if it is not completely surrounded by water [מלבי״ם, שד״ל]. Metaphorically, the nation is compared to a tiny island isolated in a stormy ocean of hostile kingdoms [ביאור שטיינזלץ]. A different perspective suggests that the reference is not to the land of Israel itself, but rather to Israelites who had actually settled on the islands surrounding Egypt [אבן עזרא].
The harsh reality sets in when the people witness the downfall of Egypt and Cush at the hands of Assyria. Seeing this collapse, they are forced to confront the fate of the very nations they had looked toward with hope and relied upon for protection [מצודת דוד, שד״ל, ביאור שטיינזלץ]. These were the empires to which they had desperately fled, seeking refuge and shelter from the terrifying threat of the Assyrian king [מצודת ציון, רד״ק]. This crushing awareness leads to a profound sense of despair. They are left with a chilling, logical deduction: if such massive, powerful empires could not withstand the Assyrian assault and failed to save even themselves, there is absolutely no way the people can escape by depending on their help [מלבי״ם, מצודת דוד, רד״ק, ביאור שטיינזלץ].