For starters, I'd say FID is most likely to work when...

1. Goals are clear, specific, and realistic (most things work best that way)

2. The foreign partner has an existing government with some capacity, both on the governance level and the military level. Trying to install governments or reanimate corpses is generally a pretty dodgy venture.

Certainly a lot more to it than that, but good places to start.

If State is more successful, that may be less due to State's capacity than due to State being more likely to lead in situations where we're cooperating with a functional government.