It seems to refer to the present and/or the future, implying that if I were to retrospect to the event, I would wonder about certain things. Really, I suspect the writer didn't like the sound of I wonder why , so he threw would in there. I can't say for sure if the past perfect is warranted here.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
pructusLooking back on the event, I would wonder why I had not been more fearful, ...~ Whenever I [would / used to] look back (past) on the event (that had happened)(more in the past), I [would / used to] wonder (habitually)(past) why I had not been more fearful (more in the past, i.e., at the time of the event), ...
CalifJimWhen you start reading the sentence, it's not clear yet where "looking back" is located in time. But when you get to "I would wonder", it becomes more clear that the idea is "When I would look back, I would wonder"Right as usual, CJ. I can't believe that didn't occur to me! That introductory phrase totally threw me off.