Once Napoleon said, there’re two ways of controlling, they’re fear and private interests. Which of these ways have positive effect in long-range?

One way or another, in life we are controlled by someone and we control someone else. Regarding the Napoleon quote, I believe interests are stronger as means of persuasion. When you know what motivates a person or a country, and you have the power to change things and situations then it's surely the best way to keep this person or the  country as your supporters and allies. Using the interests of the other party as parts of your plan to manipulate him/her, it's the best way because it's happening gently without using force or violence. This is what reality has shown us, because many wars today are economical and not physical.