The best defense would be to be invisible.  However, if a majority of a population survives a disaster, there is little to no space to disappear to.  After a few weeks , people less prepared would start roving.  There are few areas other than wilderness where you could truly hide.
We can leverage our success in a disaster in a number of ways...but the best way to survive in a SHTF situation is not to get in one to begin with.  
I have no idea how to avoid that situation though...
			






 
   
 
