A few of those ships patrolling the Sol system might be a good idea for several reasons
Think they could stop a relativistic ship aimed at us for the sole purpose of
wiping us out? See here:
http://www.projectrho.com/rocket/rocket3aa.html#killingstar
Good points about the devil we don't know being much more dangerous than
the devil we do know.
Might be wise to get some interstellar arks together, just in case.