God announced judgment on Assyria for several reasons:
They destroyed other nations without mercy (Isaiah 10:7).
They spoke with pride and dishonored God. They boasted about their own power (Isaiah 10:12).
They oppressed other peoples and took what did not belong to them (Isaiah 10:13–14).
They believed they were acting on their own. They did not recognize that God was using them (Isaiah 10:15).