Social movements benefit from third-party support in waging social change. The budding literature on the effects of social movements' strategy (violent vs. nonviolent) on third-parties' willingness to support and join the social movement has mainly regarded social movements' strategy as something fixed and unrelated to its past strategy. Using varied contexts, I investigated how social movements' past strategy may affect, if any, third parties' moral perception of the current strategy of social movements and how this perception translates into third parties' (un)willingness to support and join social movements. In the context of the conflict between hate groups and counter-protestors in a lesser-known country, Bhutan (Studies 1 & 4), and an ally country (Study 2) American participants were more willing to support and join a violent movement that was previously nonviolent as opposed to a historically violent movement. Perceived moral continuity of movements' strategy (Studies 1-5) and perceiving violent strategies as the last resort (Studies 2-4) mediated the relationship between change in movements' strategy and third parties' willingness to support and join the movement. However, using a conflictual context in which a movement, Liberation of Tamil Ealam, sought to gain independence from a government, Sri Lankan government (Study 3), and a domestic anti-Fascist movement in the United States, Antifa, that aims to combat hate groups led to partial replication of findings of Studies 1-2 & 4. While there was no significant difference between conditions (shifting from nonviolence to violence vs. continuing violence) in third parties' willingness to support and join the movement, perceived moral continuity of movements' strategy (Studies 3 & 5) and perceiving violence as the last resort (Study 3) mediated the relationship between conditions and third parties' willingness to support and join the movement. Theoretical and practical implications for social movements are discussed. Specifically, social movements that have exhausted nonviolent avenues to achieve their goals are likely to find support among third-parties for a shift toward violent strategies—support that may ultimately lead to either desired social change or conflict escalation.