Using Wikipedia's definition of Leadership: It has been described as “a process of social influence in which one person can enlist the aid and support of others in the accomplishment of a common task". With that said, forcing people to do what is wanted is one thing, having them support the vision and be contributors in the process is another.
Approaches that resort to threats (job loss, demotions, retaliation, bad reviews, etc) in order to get people to 'aid in the accomplishment of a common task', may find a few short term wins. In the long term, people will do only what they are specifically asked (forced) to do and no more as they tend to resent the effort. They do enough to get by and unless they feel like they are stuck, they will look for another environment that better suits their needs. Although not everyone has a natural tendency to be high contributors, very few like being forced to do things.
On the flip side, when the approach allows people to choose to support the vision or common task and are able to contribute to the success, it tends to generate a positive energy. That positive energy drives people to do their best, want to succeed and make contributions. With that positive energy behind them, when obstacles or needs present themselves, people tend to 'innovate' (think outside the box, find new ways of doing things, create, work things out, etc) as they maximize the use of their talents. Most people are their best self when they are appreciated and able to contribute to the overall success. Regardless of personality traits, leaders are more effective when they positively influence by allowing people to choose to support the effort rather than force.
A leader is considered successful when the task is completed (or vision achieved) and the people involved (the ones that made the journey) are better people for participating.
The challenge is handling the pressure during the effort while having to make decisions. Every leader is faced with problems, challenges, investors, etc... the leader must have an approach and should stick with that approach. Vary the tactics, make adjustments as necessary, but avoid reverting to a dictatorial leadership style just to get something completed by a certain date.