Jeremiah 50:14-15

Yahweh called Babylon’s enemies to attack her with all their strength because she had sinned against Him. The destruction should continue until the land was thoroughly ruined. She had destroyed other nations, and now she deserved the same treatment. The clause "she has given her hand" may be treaty terminology (cf. 2 Kings 10:15; Ezekiel 17:11-21).

"What is clearly in view here is treaty violation by concluding a treaty with another party." [Note: Smothers, p. 366.]