There is decided shift in Isaiah's messages from the LORD, beginning here and continuing into the next several chapters. No longer is the predicted judgment directed against the individual neighboring nations and the obvious threat is no longer the immediate Assyrian invasion. The subject now is a worldwide devastation from God Himself.
During this unprecedented time, everyone on earth will suffer loss and the devastation. Why? Verse 5 explains that the earth is defiled by human sinfulness. God's laws, statutes, and His eternal covenant have been violated.
This will be followed by a period of time when the nations from the ends of the earth will "sing for joy; over the majesty of the LORD" and "give glory to the LORD" (vv.15-16). But then, there will come a time of final judgment.
Since sin entered in the Garden of Eden, God has always been implementing His plans of redemption, judgment and cleansing the earth of its corruption. In Noah's day, He sent a worldwide flood to cleanse the earth. "But by the same word the heavens and earth that now exist are stored up for fire, being kept until the day of judgment and destruction of the ungodly." (2 Peter 3:7)
It should be remembered that God's wrath is not aimed at believers. Just as in Noah's day, He provides protection and escape from such judgment for those who turn to Him. Jesus said, "Whoever believes n the Son has eternal life; whoever does not obey the son shall not see life, but the wrath of God remains on him." (John 3:36)