Is the detachment in Duras' The Lover an aspect of anxiety, post-traumatic effect or simple narrative decision?
Having read all the material posted herein, all seem plausible. But in the end, it changes the filter to view her writing, especially here.
Any insight or even opinion would be appreciated.
You posed a great question. We know that Duras writes mostly about her life, even if she doesn't exactly write autobiographies. That being said, however, we could say that the style of The Lover tries to emulate the young Marguerite Duras's reactions to the sources of tense confusion in her life.
Remember -- she wrote The Lover later on in life, after she had had much time to reflect on what she had done and seen. Primarily for this reason, it seems inappropriate to consider The Lover as a "post-traumatic affect".
If anything, her detachment should probably be seen as a kind of minimalism that is natural for adolescents. Thus, I would say that you are right to call it a "narrative decision". It is also a way to prepare for her wordplay at various points throughout the text. Take, for example, her wordplay on the character Helene Lagonelle's name. Repeating the "L" sound over and over reminds the Francophone reader that "elle" is the French word for "she". This repetition gives us a clue about how much the young Duras was impressed -- and perhaps also how charmed by -- her pretty friend.