disproportionate response

• overreactionDisproportionate emotional response
• escalationProgressive increase in intensity
• overkillUnnecessary additional effort
• excessiveSurpassing reasonable bounds
• retaliationPunitive response to injury

vengeance · sledgehammer · nuclear · heavy-handed · revenge · punishment · backlash · fury · rage · provocation · measured · proportional · restraint · trigger · outburst · tantrum · explosion · scorched-earth