Invervension can rebuild democracy
Democracy is just the belief that a government should be by the people and for the people. I think that interventions can help rebuild a democracy that is already in place. However, I am not sure that interventions would be able to change a theocracy or dictatorship into a democracy.
Rebuild not build
There are very easy reforms that can be implemented to correct democracy - especially decentralizing decisions to smaller areas (states, for instance) and giving people a more direct hand in the decisions. It is possible to rebuild, but its not possible to build - as we have seen recently in many places.
For The People
I believe interventions can rebuild democracy. I believe in the United States democracy is seeing some of it's worst degradation, where the government no longer it believes it works for the people. I believe interventions where policy that really help the average American and they majority can right this wrong.
Intervention Won't Help Democracy
The fact of the matter is that interventions won't help rebuild democracy because that very idea makes no sense. Plus, America isn't actually a direct democracy - it's really a republic. Therefore, democracy never existed in this country as most people have come to picture democracy in all its glory.
Semi hands off approaches are required.
The one thing you have to do is let the people of a given country or region determine its own direction. While intervention the case of human rights abuses or in the case of new nuclear weapon stockpiling should be mandatory, what happens otherwise should be something left for the people who live there to figure out on their own.