An important book on leadership is, A Failure of Nerve by Edwin Friedman. I recommend that every leader read this book. The big idea of the book is that a core trait of a leader is a non-anxious presence. Described as well-differentiated, this person is able to resist the lure of emotional triangles,
which causes those in the organization to mature by influencing others to take responsibility for themselves. Check out this short video summary of Friedman's work and the concept of a non-anxious (well-differentiated) leader.