While the histories of Western grassroots movements and the officially sanctioned, communist-sponsored peace movement are well known, the independent peace activists of the Soviet bloc have remained footnotes in the history of social movements. The Group for the Establishment of Trust between East and West (the Trust Group) was the largest and most prominent unofficial peace group in the late Soviet Union. Active between 1982 and 1989, its members established significant ties with foreign peace activists. This article considers the agenda, activities and membership of the Trust Group. It contrasts the persecution experienced by this independent movement with the activities of the official, state-sanctioned Soviet Peace Committee (SPC). As the article shows, the Trust Group’s agenda resonated with the concept of ‘détente from below’, as promoted by members of European Nuclear Disarmament (END), including the historian E.P. Thompson. The article traces how Western advocates of ‘détente from below’ sought to support these independent campaigners in the Soviet Union, thus highlighting important East-West dimensions in European peace activism in the 1980s.