Project Managers as Connectors

Project managers ensure that things don’t fall between the cracks by coordinating and tracking each and every connection.  In an increasingly complex world, this has become a herculean task.  What we flipped the Project Manager’s role on its head?  

No, I don't have your back

What exactly does it mean to have someone's back?  Do they expect me to defend them unconditionally if they screw up?  Do want to know they can trust me if they take a risk?  Is this a general behavior or does it apply to a specific situation?  What does it look like when someone has your back?