Interagency collaboration among social workers, teachers, and police is key to countering violent extremism in the Nordic countries by securing comprehensive assessment of cases of concern. Yet, previous research indicates that different institutional logics—perceptions of fundamental goals, strategies, and grounds for attention in efforts to counter violent extremists—exist across professions and challenge collaboration and trust building in practice. In this article, we empirically investigate these claims across social workers (n = 1,105), teachers (n = 1,387), and police (n = 1,053) in four Nordic countries: Denmark, Sweden, Norway, and Finland. Using results from online surveys with professionals, we investigate the distribution of a ‘societal security logic’ and a ‘social care logic’ across professions and the degree to which these institutional logics translate into mutual trust. Through a comparison of institutional logics among practitioners with and without practical experience of interagency collaboration, we investigate whether and how institutional logics tend to mix and merge in hybrid organizational spaces. We conclude that differences in institutional logics across professions are differences in degree rather than in kind, but that such differences are important in shaping mutual trust and that experiences of interagency collaboration are correlated with a convergence toward a ‘social care logic’ conception of countering violent extremism.