Should there be a law protecting deployed service personnel from being served with a divorce?
No, forbidding it outright would cut into too many freedoms. What could be done is a special law that would effectively freeze the proceedings and make it a crime to appropriate possessions.
This would protect the serviceman/-woman from coming home and facing the fact that his ex took everything he/she owned.
Because it seems to me that divorcing someone who is away and likely undergoing trauma in the service of their country is a low and repugnant act.
Of course it is low, but we humans define ourselves by the ability to go lower than a snake full of buckshot.