This passage is quite difficult to interpret. It can be seen as a taunting of the nations, or it can be seen as a literal destruction of the Syro-Palestinian land, and this seems to be the favoured interpretation. The whole message of the chapters around this is that the leaders (the shepherds) of Israel have failed her, but that the Lord Himself would become her shepherd and then salvation would come. The supreme failure of Israel’s leaders was their rejection of the Messiah when He came. Soon after that Rome destroyed Jerusalem and the temple in AD70.
We get a terrible picture here of the way that the shepherds had led Israel. They were supposed to lead the people in the ways of the Lord, but all they did was look after themselves, and seek their own well being. So the flock is marked for slaughter, and slaughter did indeed come. We should note that there is a twofold judgement here. The leaders are the primary guilty ones, but the people themselves will suffer as well. We all have responsibility. Many church leaders today should pay heed to these verses. We are there to lead the people in the way of the Lord, not in the way of the world.