The one topic that is seldom discussed in the workplace but is absolutely crucial to effective leadership is courage.
Most employee relations lawsuits come about because someone, somewhere, was reluctant to confront the problem while it was small. They ignored it and played "Let's pretend it's not there" and the problem grew into some attorney's creature.
Courage is not discussed because it's one of those personal things you are supposed to have and if you don't have it, for God's sake don't tell us because then we might have to address your problems for you and we have a little problem with that courage thing ourselves. As a result, lack of courage is usually a group problem. The supervisor lacks the guts to confront the difficult employee because he or she knows that the folks in upper management in turn lack the guts to support firm action.
[I once provided advice on a situation where a supervisor had waved a gun around, showed up drunk, threatened employees and fondled women. When upper management was briefed on the matter, one of the executive suite wizards asked, "Can't we find a desk for this guy somewhere?"
It's a safe bet that he didn't want the desk next to his own.]
How do you get courage? By doing courageous things. That's how the military and police and fire departments train their recruits. They teach them to behave illogically by forcing them to move toward, instead of away from, danger. They drill and drill again so that certain actions become second nature and self-confidence grows.
The same approach can be taken in small steps in the workplace. The phone message you don't want to return? That's the first task you should tackle. The difficult employee who needs to be turned around? Sit down and talk about the specific performance problem in clear, no-nonsense terms. It won't be easy the first or second or even the tenth time but it will get easier and, some day, the actions that you regard as standard will be worthy of being called courageous.