In societies involved in an intractable conflict, there are strong socio-psychological barriers that contribute to the continuation and intractability of the conflict. Based on a unique field study conducted in the context of the Israeli-Palestinian conflict, we offer a new avenue to overcome these barriers by exposing participants to a long-term paradoxical intervention campaign expressing extreme ideas that are congruent with the shared ethos of conflict. Results show that the intervention, although counterintuitive, led participants to express more conciliatory attitudes regarding the conflict, particularly among participants with center and right political orientation. Most importantly, the intervention even influenced participants' actual voting patterns in the 2013 Israeli general elections: Participants who were exposed to the paradoxical intervention, which took place in proximity to the general elections, reported that they tended to vote more for dovish parties, which advocate a peaceful resolution to the conflict. These effects were long lasting, as the participants in the intervention condition expressed more conciliatory attitudes when they were reassessed 1 y after the intervention. Based on these results, we propose a new layer to the general theory of persuasion based on the concept of paradoxical thinking.attitude change | psychological intervention I n recent years, the study of intractable conflicts has gained prominence within the social sciences (1, 2). This type of conflict is very difficult to resolve peacefully because it is fueled by socio-psychological barriers that play a key role in this impasse (3, 4). One major implication of these barriers is the tendency to freeze on conflict supporting societal beliefs and attitudes, and thus preserve hostility between the adversaries (5, 6). [Societal beliefs are defined as shared cognitions by society members that address themes and issues that society members are particularly occupied with, and which contribute to their sense of uniqueness (7).]Freezing is characterized by rigidity and close-mindedness, such that information incongruent with the reigning cognitiveemotional structure is likely to be ignored, rejected, misinterpreted, or forgotten, whereas congruent information is accepted as valid (8, 9; see also ref. 10). In fact, cognitive freezing encourages tunnel vision with respect to the conflict and the means to resolve it. Thus, one major challenge for scholars and peace activists is to overcome these deeply rooted socio-psychological barriers by unfreezing the held conflict supporting collective narratives. A successful unfreezing process should increase the individual's openness to previously contradictory views regarding the conflict, the adversary, and the in-group (5). With this challenge, a growing body of research has attempted to identify methods of intervention that can unfreeze deeply rooted conflict-supporting narratives among groups in conflict (11-16).In principle, most current interventions directly provide information th...