I think the idea is one of them is convincing someone to not do something they still have the power to do, while the other would be taking that power away completely. There may be a truly foolproof way to disarm a weapon, but there will never be a foolproof way to convince someone of anything due to the unpredictability of people.
Does anyone actually want to answer the question?
Edit:
If we are just parsing language, here is my meaning:
prevent the violent force
I think the idea is one of them is convincing someone to not do something they still have the power to do, while the other would be taking that power away completely. There may be a truly foolproof way to disarm a weapon, but there will never be a foolproof way to convince someone of anything due to the unpredictability of people.