fomenting instability

Khaldoun-

I don't know of such documentation vis a vis imperial decline, but there
is solid documentation in the case of Italy of what was called the
"Strategy of Tension," which involved the state creating "right-wing" 
terrorist groups which engaged in violence (most spectacularly a bombing
in a Bologna train station, if I remember correctly, which killed dozens),
and then "justified" state repression aimed, of course, at the Left.  This
was in the period of the late 70s into the 80s.

Unfortunately I don't have a citation at my fingertips, but I know there's
at least one book-length work on the subject.

RH