Pacifist: It is immoral to do anything that causes harm to another person.
Conclusion
It is immoral to threaten to use force, even in self-defense.
Evidence (since)
It is immoral to do anything that causes harm to another person.
Using force causes harm to another person
Evaluate
The two premises have a common concept, causes harm to another person. Our Inference-brain should read these first two ideas and synthesize them. It's a conditional rule and a specific case to which we can apply that rule.
RULE: if causes harm, immoral SPECIFIC: using-force causes harm INFER: using-force is immoral
Once we've merged the two premises into one, it's easier to hear the gap:
Using force is immoral. Thus, threatening to use force (even in self-defense) is immoral.
Goal
Look for something like, .