We hear a lot about how God is a God of love and that is the truth, but this kind of love extends far beyond just a feeling. This is the kind of love that wants the best for the object of its affection. It is a protective, compassionate, love that is driven for the growth and well-being of the ones that are loved. This love will be as tough as it needs to be to get to what it must have, by its very nature. This is a love of justice first and foremost, and a desire for those God created to become like Himself.
That type of love will express itself in wrath. It cannot be any other way. That passion includes protection for the beloved and a demand for the right, even from His beloved. We see it reflected in the passion of a momma bear--protective and unyielding, first to any attacker, but also in correcting her own. In Isaiah 10, God shows his wrath against unfair judges and their treatment of the poor and oppressed. In response, He sends Assyria as a tool to correct those judges, but their love of violence makes them the next target for His wrath. Similarly, God chooses to use the Babylonians as a tool of correction for Israel's idolatry and injustice, but their cruelty does not go unpunished either.
That's one of the reasons so many of these passages ultimately include promises of a Messiah that will execute God's justice rightly. His wrath will be sure and final, but only toward those who abuse others and reject His leadership. Peace cannot be had when men oppose an omnipotent God.
If we measure our offenses by the scales that compare our sins to others, we might be able to get the scales to balance or come close but that's not the scales that will be used. The wages (balancing punishment) for sin--any sin--is death. His justice cannot abide the affront to His righteousness or the offense to His other children. It is amazing that there is any rescue afforded at all.
That's why chapter 12 is so profound. He provides our salvation so that His anger can be satisfied, therefore:
“I will praise you, O Lord!
You were angry with me, but not any more.
Now you comfort me.
See, God has come to save me.
I will trust in him and not be afraid."