Regime change is achieved only after "convincing" the people that the end state that you believe best is actually good for them. Putting democracy in a place like Afghanistan is probably fruitless, but putting a free-market system in Russia would work pretty well -- as long as the people believe that what you are trying to accomplish will work. And persuasion, on this planet, is useless without force. We had eight years of the former sans the latter and we see how that worked.