fáng huàn
preventative measures
to guard against accident or disaster
fáng huàn wèi rán
to prevent troubles before the event (idiom)
to forestall
to nip sth in the bud
fáng huàn wèi méng
to prevent a disaster before the event (idiom); to nip sth in the bud
fáng huàn yú wèi rán
see 防患未然[fang2 huan4 wei4 ran2]