The Indian trade union movement of the interwar years was marked by an increasing tension between reformist and revolutionary methods. The two factions shared an internationalist idiom and internationalist aspirations, but their visions of the postimperialist world order were crucially different. The reformists advocated inclusion of India’s labour leaders in the international system, whereas the revolutionaries sought to harness international workers’ solidarity to overthrow it. The Meerut Conspiracy Case exacerbated these tensions in AITUC by specifically targeting left-wing trade union leaders and by including international trade union bodies in the indictment. AITUC split during the first year of the case, and it fragmented further as the case progressed. Stolte’s article views Meerut as a case in which trade unionism itself was put on trial. It made emerging (re)definitions of revolutionary and reformist trade unionism explicit, and it situated both in an international environment and on divergent international trajectories. During the Meerut case, trade union politics were debated inside and outside the courtroom. This worsened the tensions between reformist and revolutionary trade unionism. First, the indictment created “good” and “seditious” international interlocutors for the unionists. Second, the reformist methods of seeking inclusion in the ILO and other existing European bodies were vocally attacked by the Meerut accused. Finally, the accused stayed in conversation with the revolutionary leadership of the AITUC throughout the trial. The debates on trade unionism thus created were decisive in making the Nagpur split permanent.