Answer: One development in Europe that led to the creation of new states in the period 1910-1920 was the dissolution of the Austro-Hungarian Empire after World War I. The Austro-Hungarian Empire was a multiethnic empire that had controlled much of Central and Eastern Europe for centuries, but it faced significant challenges as the empire became increasingly diverse and its constituent nationalities began to demand greater autonomy.
During World War I, the empire was weakened by military defeats and internal unrest, and in 1918 it was dissolved. The dissolution of the Austro-Hungarian Empire led to the creation of several new states, including Czechoslovakia, Yugoslavia, and Austria. These new states were formed along ethnic and linguistic lines, reflecting the aspirations of different nationalities for self-determination.
The creation of these new states had a significant impact on the political landscape of Europe in the post-World War I period. It led to the emergence of new democracies and new international relationships, as well as to tensions and conflicts between different nationalities and states. The dissolution of the Austro-Hungarian Empire also contributed to the rise of nationalism and the formation of new alliances, ultimately shaping the course of European history in the twentieth century.