Tendency to get equilibrium in secret police, nothing succeeded externally (11)

'tendency to get equilibrium' is the definition.
I can't tell whether this defines the answer.

'in secret police nothing succeeded externally' is the wordplay.
'in' becomes 'home' ('he's in' can mean 'he's home').
'secret police' becomes 'stasi' (state security service of the GDR, East Germany).
'nothing' becomes 'O' (looks like zero - 0).
'succeeded' becomes 's' (genealogical abbreviation).
'externally' means one lot of letters goes inside another (some letters go on the outside of others).
'o'+'s'='os'
'stasi' inserted within 'os' is 'ostasis'.
'home'+'ostasis'='HOMEOSTASIS'

Can you help me to learn more?