Abstract: Social movement studies have constantly focused on research relating to movement strategy, without reaching a consensus on the most viable strategies for realising a movement’s goal. Instead of conceptualising movement strategy as merely a product of movement leaders’ rational calculations, this article analyses a case of strategy shift attributable to leadership replacement and unexpected events. This article examines the significant breakthroughs achieved by Taiwan’s anti-nuclear movement following Japan’s Fukushima Incident in 2011, as well as the 2014 Sunflower Movement in Taiwan. It argues that a militant citizen movement came into being because a new wave of activism employed non-partisan leadership and demonstrated a willingness to employ disruptive tactics. Mounting protests generated a split among members of the traditionally pro-nuclear Kuomintang political party, which was forced to halt the construction of the fourth nuclear power plant in 2014. With the regime change in 2016 that brought the more environment-friendly Democratic Progressive Party to power, Taiwan is now on course to phase out nuclear energy.