This article studies the constitution of the Colombian section of the Anti-Imperialist League of the Americas. From a perspective that suggests overcoming certain localist readings, it is argued that the participation of Colombian socialism in this anti-imperialist network brought modifications that allowed local socialists to participate more decisively in the debates and practical initiatives of organizations derived from the Communist International. Thus, the creation of the League section constitutes a new attempt by socialism to establish links with organizations of international socialism and communism. On the other hand, participation in the League represented a boost for the activities of the PSR, but it was also a place of controversy over alliances and internal divisions that were mediated by the readings made by the Socialists about the Russian revolution. In this sense, the organization of the Colombian section of the League would reveal the disputes and tensions that were expressed among several members of the PSR about the future of this organization and the political proposals for change.