True, any restraining/Stalking Order is only as "effective" as the honor/dishonor of the person to be restrained,
BUTBUTBUTBUT
It also *can* provide a valuable element in a paper trail documenting the good person's innocence and diligence, and the bad person's propensity to violence.
Plus, if your opponent is truly wacko, it can trigger the confrontation that leads to a decisive solution...or the suicide that ends the problem.
In either case, the outcome can be positive for the entire world.
Also activate the grievance procedure and apply for an exemption at work from the no weapons policy, based on known, specific threats to an identifiable person, from another identifiable person. If refused, then ask for an armed security guard at the front. Watch management squirm. When faced with the nonproductive staffing costs of full-time security, they just might grant the exemption. If they still resist, ask them to rent you a Kevlar vest.
IMMEDIATELY, get creative with the weapons policy and arrange for other nice "expedient" non-obvious weapons to be in easy reach at all times. Think distance! .