Bei Dao’s early work was rarely overtly political. But as Mr. Weinberger writes in a perceptive biographical note, his poetry’s “assertion of individual sentiments and perceptions, of imagination itself, was considered subversive in a collectivist society.” Bei Dao’s poem “The Answer,” Mr. Weinberger notes, was the “Blowin’ in the Wind” of China’s democracy movement of the late 1970s.