One of the most important Project Management skills

Currently I think that the one of the most important Project Management skills is the Vision of the result.

So PM may not know how exactly things go and created, but it is vitally important for PM to know how complete things must look like. Sure the result have to be achievable (sometimes we can imagine such impossible things...)
And PM must be able to inspire his or her team to implement such Vision.

Well, the formula is quite simple "The Result = Vision + Possibility to Implement".

I'm sure these simple principles can be obtained from careful reading of books (and important SMART model), but as a rule information in books is digged in and sometimes it is not easy to get it correctly.