Control or Be Controlled

To say that there is no one coming to help -
does not mean that no one is coming.

When a society ceases to function -

all sorts of people come.

It is much like when an animal dies beside the road -
there are other animals that will come and eat it.
It doesn't have to be dead.
Just wounded and it is a goner.

People sitting there after a nuclear war -
are definitely wounded.

If they are alone, any predator can pick them off separately.
Even a community that is not prepared -
is prey. 

Biker gangs and criminal groups are already organized.

Americans don't  like to think that their military
could go renegade,
but it has lots of times in the past.

The local police force is very likely to quit functioning.

Individual members will be busy looking after their individual families.

Those who prey, may be more subtle.
They may be the remnant of government past -
and working on the basis to benefit themselves.

The answer to any of this is that you must organize with your neighbors - to protect yourself.