Nationalism in the Twentieth Century In the twentieth century world there has been a growing shift towards a sense of nationalism in many countries around the world. There was a great deal of change during this time due to the changes made during both world wars and the effects of what happened after them. Looking at the world from the end of World War I to the end of World War II there is an immediate difference between the two worlds. From 1919 to 1945 there was a difference not only in how people acted, but also in how situations were handled between different countries. National relations were different from 1919 to 1945 because many leaders in each country felt differently at the end of each war. Looking back at the twentieth century and observing the differences between 1919 and 1945 there was a big difference between the two worlds. . After World War I, relations between the two countries were neither bad nor good. There were not many negative feelings after World War I, and the issues that caused the war were mostly resolved. Germany was the only country still truly bitter about the outcome of the First World War. After World War I there were what historians called the interwar years. This was the period from 1918 to 1939 and was the period between the two world wars. During this period there were many advances not only in the military field but also in the economies of different countries. During this time the United States went through a decade of the 1920s and then went through a terrible depression. The English during this period faced revolts in their various colonies and landholdings around the world. They made people leave their total protection and get their own forms of parliament and lost men fighting and dealing with the different riots in Ireland, Kenya,