This paper argues, through a case study of two industry-wide strikes in the Korean banking sector, that a proactive interventionist strike is more effective than a reactive pragmatist one in a union’s response to restructuring. Evidence from the two strikes shows that unions were able to achieve more successful outcomes from the strike in which they engaged proactively by an interventionist mode. In this case the unions identified opportunities, took the initiative and devised effective strategies that pre-empted the other parties before they had fully prepared their restructuring planning. Such a strategic capacity was gained from active organizational learning in unions derived from their previous strike failure.