Some translations set poetry farther to the right than the rest of the text to show that it is poetry. The ULB does this with the poetry in this chapter.
When Israel was conquered, they were being punished for their sin. Yahweh is strong enough to deliver them, but he did not because he desired to refine them through the experience of the exile. (See: [[rc://en/tw/dict/bible/other/deliverer]] and [[rc://en/tw/dict/bible/kt/sin]])