struggles and crises Jim faces in his own life.  At the same time, from a thematic point of view, I think that teens would identify with Jim's struggle because it reflects the challenges of living in the modern setting.  Teens would recognize and empathize with Jim's predicament in having to deal with a situation that is beyond his control.  Jim did not cause the war nor does he benefit from it. Yet, he is forced to deal with it.  Teens could understand this predicament in that they themselves find themselves having to deal with realities that they have not constructed.  In this, I think that there would be an instant identification with Jim from the modern teen readers.  Finally, the ending is one in which a dual consciousness emerges.  Jim's brain and psyche operates as a paralell processor.  Consider the ending thoughts to substantiate this:

...only part of his [Jim's] mind would leave Shanghai. The rest would remain there forever, returning on the tide like the coffins launched from the funeral piers at Nantao.

This condition in which Jim's mind exists in both present and past is reflective of much in way of the teenager's mind.  The notion of mental construction as evaluating and judging over time events of the past while in the present is something that the teen reader could make instant identification with in reading about Jim's predicament.