Until Russia’s full-scale invasion of Ukraine in February 2022, many radical left and right parties in (North-)Western Europe showed sympathies for Putin’s Russia and held the USA and NATO (co-)responsible for the armed conflict in the Donbas and the annexation of Crimea. Since the full-scale invasion, some parties on the radical left and right have repositioned themselves as supporters of Ukraine against Russia; others have stayed on a course of equidistance to the conflict parties; yet others experience fierce intra-party arguments over the appropriate response or even split over the issue. We examine the role of ideological factors, such as anti-Americanism and hawkishness, as well as factors of the political system, such as the number of parties competing for radical left or right voters and parties’ position in government or opposition to better understand the dynamics of thirteen radical parties’ (re-)positioning in four countries: Finland, Germany, the Netherlands, and Italy. We find that both party ideology dynamics of competition within the party systems affect radical parties’ positioning on the Ukraine crisis. We also acknowledge a significant extent of variation across countries, in terms of content of the debate and radical parties’ positioning. All in all, the article contributes to the understanding of European radical parties’ viewpoints on foreign policy and their relationship with Putin’s Russia.