Behold, I will send and take all the families of the north, saith the LORD, and Nebuchadrezzar the king of Babylon, my servant, and will bring them against this land, and against the inhabitants thereof, and against all these nations round about, and will utterly destroy them, and make them an astonishment, and an hissing, and perpetual desolations.
The north - (note, Jeremiah 1:14-15). The Medes and other northern peoples confederate with Babylon are included with the Chaldeans.
Nebuchadnezzar ... my servant - my agent for punishing (Jeremiah 27:6; Jeremiah 43:10: cf. Jeremiah 40:2, which shows that Nehuzaradan, Nebuchadnezzar's captain, had even some consciousness of the divine mission which the Babylonian king fulfilled, in accordance with Jeremiah's prophecy - "The Lord thy God," said he to Jeremiah, "hath pronounced this evil upon this place"). Compare Isaiah 44:28, Cyrus, "my shepherd." God makes even unbelievers unconsciously to fulfill His designs. A reproof to the Jews, who boasted that they were the servants of God; yet a pagan king is to be more the servant of God than they, and that as the agent of their punishment.