[muskah]

It has been a long time, but I seem to recall that “intent” plays a role in deciding if it is desertion or AWOL. If he intended to return it would be AWOL. His capture makes that distinction hard to determine. Is the fact that they were in a combat zone important?

[oh8eleven]

It has been a long time, but I seem to recall that “intent” plays a role in deciding if it is desertion or AWOL.
Been a long time for me too, but IIRC, you're AWOL for the first 30 days you're gone, then it becomes desertion.
Intent has nothing to do with it.

[Bob]

Combat zone or not, his sending off of personal effects in the days before leaving strongly indicates that he intended to not return. Coupled with his emails, a strong case for desertion should be able to be put together fairly quickly.