crack the whip

Short definition from Wiktionary

Verb

1. 1
   To make harsh demands in a position of leadership.

Noun

1. 1
   Alternative form of crack-the-whip.
2. 2
   An outdoor children's game in which participants try to maintain hold of hands as random movements by the leader at the head of the line increase the force at the tail, as with the end of a whip.
3. 3
   Any maneuver in a variety of disciplines that mimics the motion of the tail of a whip.