Jeremiah - Chapter 12
Why Do the Wicked Prosper?
Jeremiah says that he knows that G-d is by definition always right, but that he still engages in debate with Him so that he can better understand G-d's ways. He then asks G-d why the wicked are allowed to prosper. (Rashi says Jeremiah specifically asked why Nebuchadnezzar was allowed to achieve such greatness.) G-d plants these people, allowing them to flourish. Sometimes they give lip service to G-d, but they never serve Him for real. On the other hand, G-d knows that Jeremiah serves Him sincerely; He saved Jeremiah from the plotters of Anasos, whom He will punish. How long will the land be desolate?
G-d replies to Jeremiah's question that the sins of the people have caused the exile; they thought that G-d could not foresee their end. Just like a person who can't keep up with runners has no chance of keeping pace with horses, similarly if Jeremiah can't be safe in his hometown, what chance would he have in another land? The plotters were his own kinsmen and they tried to kill him! He must not trust them, even if they act civilly towards him.
G-d continues that He is "cutting His losses" - He's giving up on the Temple and the nation, allowing them to fall into enemy hands. The Jewish people treated G-d like a lion in the forest treats people passing through - they "roared" against Him, antagonizing Him. Are they a blood-stained bird of prey that other birds surround to attack, inviting the animals of the field to eat the remains? The generals of the Babylonian army (who are "shepherds" to their troops) will trample the land, turning it into a wasteland. Plunderers come to pillage the land, which has been laid waste from end to end by Nebuchadnezzar, acting on G-d's behalf. The people plant wheat, but thorns come up instead. They cry out from their troubles, but G-d will not listen.
Finally, G-d says regarding the countries neighboring Israel that He will exile them, as well. After He does so, they, too, will eventually return to their land - but only if they learn a lesson from the Jews. They have to learn from the Jews to serve G-d, just as they previously taught the Jews to serve idols. If they don't, then that nation will be gone for good. (You'll notice that many of our ancient neighbors are gone, but look how much of the non-Jewish world now worships G-d, albeit differently than we do.)