What are the similarities and differences between the major political, economic, and social developments in the first half of the twentieth century and those in the second half of the century? Solution Similarities: There were some similarities between the first half and second half of twentieth century. In both times, world economy was chacterised by the fluctuations and there was tug of war for usurping the political power. In both time whole world was divided between the two parts. Both times, world leader were seeking to establish the peace and tranquilities. Differences: In the second half, unlike the first half, many countries got freedom from colonialism and they started fight for equal status in the international arena. Social and economic development got the preference over the colonialism. World was divided in the two blocks one being represented by the USSR and another by USA. Both blocks were giving many incentives to enlist the support of developing countries..