She thinks that everyone should be given a unique barcode at birth because that would make it easier to identify anyone. She's correct in that assertion, but really struggles to connect this to "and therefore this is a good idea":
Having such a unique barcode would have many advantages. In war soldiers could easily differentiate legitimate targets in a population from non combatants.
This could prevent mistakes in identity, mistakes that result in the deaths of innocent bystanders.
Yes. Um. So you take the population database and run a filter to set the "innocent" Boolean field appropriately, distribute that database to all weapons in the field, and everyone's happy.
For someone who's a science fiction author and History BA, Elizabeth Moon sure didn't pay much attention in the important history classes.