Judgment is certain now, because of Judah's impenitency. All that is left for Jeremiah is to tell the people to run for their lives from the judicial destruction and occupation of Judah by evil Babylon from the north.
Judah, weakened and frail because of her adultery, will be easy prey. Spiritual emaciation precedes economic and military emaciation. And military strength without spiritual and moral strength is not enough to guarantee the security of a nation.