While the Great War is at the top of everyone's minds, the mundane realities of life do not stop. Bandit raids, monster hordes, errands for important ingredients, all jobs are still available for the taking. Thus, adventuring is still seen as a legitimate profession, though with stipulations.
Everyone is expected to do their part. Even if you are a soldier, you are allowed to take time to deal with these internal issues, and you will not be seen as a deserter for doing so. That being said, expect your group to be called on if they make a big enough name for themselves. Your party may be asked to infiltrate an Imperial supply camp, clear out territories for use by the Alliance, or even engaging in the large-scale battles if necessary. If you are able-bodied enough to be an adventurer, you know that should the Empire prevail, you will be expected to serve on their front lines as fodder. Ignoring the threat is simply not feasible.