The World Council of Churches, as well as the ecumenical movement as a whole, were severely criticized after the fall of the “Iron curtain”. On the one hand, this organization was accused of loyal politics towards the socialist countries and neglecting the restrictions of religious freedoms. On the other hand, it was accused of active participation in the loss of theological identity of Churches with ancient traditions. This article analyses the development of the World Council of Churches, the change of its theological and social doctrines in the context of ideological opposition between two political blocks, active processes of decolonization in the South and secularization in the West. The author ofers an analysis from inside —  this helps to understand the values of its leaders, the logic of their actions, the mechanisms of planning and decision‑making. Gradual shift of attention of  the World Council of Churches in the 1960s to the Third World led to the shift of the theological paradigm of ecumenical movement: now it was more about theology of liberation and emphasis on the image of the “Church for the poor”. This shift created more opportunities for dialogue with representatives of Churches from the socialist camp.