"'I will turn her into a place for owls and into swampland; I will sweep her with the broom of destruction,' declares the Lord Almighty." NIV translation
The focus shifts back to the Babylon of Isaiah's day and the judgment that fell upon it. This passage has been carried out as the ancient city of Babylon that is located in Iraq is not inhabited by anyone.
"The Lord Almighty has sworn, 'Surely, as I have planned, so it will be, and as I have purposed, so it will stand.'" NIV translation
If God says it, then, it is going to happen and He has His purposes for all things. The Babylon that we saw judged had not even came to power at the time that this prophecy was delivered but it was going to come to fulfill God's purpose.
In the same way, God has a plan and a purpose for His people as a group and also as individuals. He has made plans for all of us and they will be fulfilled.
"'I will crush the Assyrian in my land; on my mountains I will trample him down. His yoke will be taken from my people, and his burden removed from their shoulders.' This is the plan determined for the whole world; this is the hand stretched out over all nations. For the Lord Almighty has purposed, and who can thwart him? His hand is stretched out, and who can turn it back?" NIV translation
At the time of this prophecy, the Assyrian empire was the greatest and most feared. They had oppressed God's people and so He raised up the Babylonians to defeat them.
We see from this passage that it is God's plan to deal with all nations that mess with His people. We are reminded that He is in control and no nation can stand against His purpose. That was true in Isaiah's day and it is just as true today.
"This oracle came in the year King Ahaz died: Do not rejoice, all you Philistines, that the rod that struck you is broken; from the root of that snake will spring up a viper, its fruit will be a darting venomous serpent. The poorest of the poor will find pasture, and the needy will lie down in safety. But your root I will destroy by famine; it will slay your survivors." NIV translation
This warning was given to the Philistines which were in the coastal area of Israel. Syria and Israel had joined forces against Judah and they had captured parts of the land. They are warned that worse is yet to come.
"Wail, O gate! Howl, O city! Melt away, all you Philistines! A cloud of smoke comes from the north, and there is not a straggler in its ranks. What answer shall be given to the envoys of that nation? 'The Lord has established Zion, and in her his afflicted people will find refuge.'" NIV translation
The Assyrians conquered Syria and Jerusalem was saved from them. We see, here, that it is God who has established this land and this city for His people. It is how it was during this time and it is the same today.