bugging
cloak-and-dagger work
counterintelligence
electronic surveillance
espial
espionage
following
intelligence
intelligence work
military intelligence
observation
secret police
secret service
shadowing
spying
stakeout
surveillance
tailing
trailing
wiretap
wiretapping
antiterrorism
backstabbing
basedin
brass-handled
commonweal
delation
destabilization
environmentalprotection
ex-estate
ruination
speakers'
theforeign
walnut-wood
war
water-holding