Whenever undiscussables exist, their existence is also undiscussable. Moreover, both are covered up, because rules that make important issues undiscussables violate espoused norms... It is very difficult to manage [organizational defense routines]. They continue to exist and proliferate because they are relegated to the realm of "underground management” and all sides tacitly agree to this state of affairs. As a result, organizational defense routines often are very powerful.