2 Kings 17:18
Therefore the LORD was very angry with Israel, and removed them out of his sight: there was none left but the tribe of Judah only. Therefore the LORD was very angry with Israel, and removed them out of his sight: there was none left but the tribe of Judah only.
Therefore the Lord was very angry with Israel because of persistent unfaithfulness in rejecting his commandments and covenant and his ways for idolatry and wicked practices, for human ways and heathen practices. The exile came only after the people refused repeated warnings through the prophets and repeated calls to repent and turn back to him. In that great anger he afflicted them and delivered them into the hands of their enemies until they were cast out of the land.
That removal meant the fall of Samaria and the scattering of the ten tribes out of the land and out of his sight and presence. None were left but the tribe of Judah only. Having rejected God for the practices of other nations, Israel fell and became prey to the very nations it had chosen to follow. The downfall that began with that rejection continued until that outcome was complete.
Their captivity exposed how weak they were without God. Their defeat caused the surrounding nations to question the power of Israel's God.