The first theme was sin, which leads automatically to the second theme: suffering. The suffering inflicted on Judah (and other places) for sinning is pretty significant. Cities are destroyed, people are reduced to poverty and starvation. There's lots of wandering around in sackcloth (not too comfy, gang), plus lots of weeping and wailing. But Isaiah isn't just depicting suffering, he's attempting to show its causes. He aims to show how the injustice of human beings rebounds like a really awful boomerang right back at them.
Questions About Suffering
Is suffering ultimately meaningful? Or does the kind of pain depicted here ultimately without any "gain" balancing it out at the end?
Do only guilty people suffer in Isaiah? Or do the innocent suffer along with the guilty?
How do people react to their suffering? Are their people who learn no lessons from it (if there are always lessons to be learned from it)?
Does suffering actually help improve Judah? Is it laying the groundwork for a better order, a better time?