Jeremiah 12:17

But if they will not obey, I will utterly pluck up and destroy that nation, saith the LORD.

Persistent disobedience brings a nation's destruction, and this warning belongs to Jeremiah's denunciation of Israel's idolatry and willfulness with punishment soon to come through Babylon. In the wider passage the nations that harmed Israel's inheritance would be removed from the land, yet they could be welcomed among God's people if they learned His ways and worshiped Him rather than Baal. If they would not obey, God would utterly pluck up and destroy that nation, bringing total removal and ruin through being uprooted and destroyed.

The verse is God's plain and awful denunciation against sin. Belonging to God's people depends on character and obedience, not birth. The warning stands as a touching appeal to return to God, spoken in sorrow of heart over the people's transgression, which the mass of the people met with utter lack of response.