The present study explores the impact of nonviolent communication (NVC) intervention on advantaged group members’ participation in collective action on behalf of disadvantaged outgroups, also known as solidarity based collective action (SBCA). It also examines the mediating role of hope and empathy in this process. In many cases there is a need to mobilize the advantage group to act on behalf of the disadvantaged group to create social change. Although the vast literature on collective action, little is known on how to promote it especially in the context of intractable conflicts. Based on previous studies showing the effects of malleable word view and perspective taking we assumed that an NVC intervention that includes these components will affect SBCA. Driving from previous literature establishing emotions as an important drive in motivation and behavior in intergroup relation we assumed that hope and empathy will mediate this affect.Using an experimental longitudinal field study in the context of the Israeli-Palestinian conflict, Jewish Israelis (N=216) were randomly assigned either to NVC or to a control condition. Results indicated that, relative to the control, participants in the NVC condition showed an increased tendency to engage in activities that are considered part of SBCA six weeks after the intervention. Furthermore, the NVC intervention affected both hope and empathy by maintaining higher levels of hope six weeks after intervention and by increasing empathy immediately after intervention. Yet hope, but not empathy, mediated the effect of the NVC intervention on participation in SBCA. Theoretical and applicable implications are discussed.