Du Fu's Spring Hope was written during the war, when the author lived in Chang 'an. What kind of background can be seen from the poem?

Chang 'an was captured by the disorderly army (that is, the poet said "the country was broken"). It was spring and there was chaos everywhere. The flowers were destroyed, the bird's nest overturned and the vegetation grew wildly. Many broken houses are almost buried, and no one is cleaning them up.

The war has been going on for three months, and there is no letter from home or news from family.