The development of Europe greatly changed due to imperialistic desires and nationalism. This imperialism and nationalism is responsible for the increase in competition among nations which leads to conflicts between that would disturb the world peace in 1914 when the World War I started. Commercial Revolution in Europe created new needs and desires for wealth and raw materials which leads to colonization of distant parts of the world. The powerful European countries attack on the countries for taking its resources and fulfill economic goals. Due to this imperialism and nationalism, weak nation comes under the group of power nations which creates international allegiances.
<span>According to William H. McNeill, one way the plague affected China after 1331 was that it reduced the population drastically and led to economic depression. </span>
