The term 'BIG ___ CONFERENCE' is composed of three crossword solutions: EAST (4 letters), TEN (3 letters), and YALTA (5 letters). The first solution, EAST, refers to the Eastern Bloc countries of the Soviet Union during the Cold War. The second solution, TEN, is a reference to the TEN-Nation Disarmament Committee, which was established in Geneva in 1959. The third solution, YALTA, is a reference to the 1945 Yalta Conference, which was a meeting between the leaders of the United States, the United Kingdom, and the Soviet Union to discuss the post-World War II reorganization of Europe. Together, these three solutions refer to the Big Three Conferences of the Cold War era, which were held to discuss the political and military issues of the time.