Always be positive, especially during times of crisis or adversity. It is the number one most admired character trait of a leader in civilian, military, and business. It is easily the most important leadership principle.
“Courage is rightly esteemed the first of human qualities because it is the quality which guarantees all others.” Winston Churchill
To stay positive and inspire others to perform to the best of their abilities, even when failure might be the only foreseeable outcome, separates true leaders from wannabes.