After the Russian invasion of Ukraine in 2022, the democratic backslider parties in Hungary (Fidesz) and Poland (Law and Justice) took conflicting positions on Russia, putting their ongoing cooperation in the Rule of Law (RoL) conflict and within the broader alliance of populist radical right (PRR) parties in question. Building on and advancing the theoretical framework of democratic backsliding, PRR party cooperation and authoritarian diffusion, we assess the impact of exogenous shocks triggered by external authoritarian actors on these types of cooperation. We examine the voting patterns of Fidesz, Law and Justice and other PRR parties in the European Parliament (EP), considering their assertiveness towards Russia and the RoL conflict before and after the full-scale invasion. We find that although the invasion made the PRR parties converge on their levels of assertiveness towards Russia, it remains a divisive issue. Moreover, the invasion did not influence the dynamics of democratic backsliding.