Throughout history there have been many reasons that a nation has been united or torn apart. One of the main reasons is the feeling of nationalism which is a strong sense of pride toward one's country. Nationalism played a big role in both the unification of the German states and the decline and breakup of the Ottoman Empire. .
Before 1848, Germany consisted of a number of independent states that all had separate governments. During this period of time there were many attempts to unify the states but none of them were successful. Then in 1862, Otto von Bismarck became the Prussian chancellor, and he had big plans for his country. He intended to unite Germany under Prussian rule while stopping any liberal advances at the same time. Bismarck believed that he could achieve his goals by controlling the people and manipulating them for his purposes, through the use of charismatic leaders, the granting of limited power, or even the use of the army. He wanted to gain the support of the lower class and gain a popular vote that he could use against the liberals and Austria. This lead him to believe nationalism was the best way to get German people behind him. He believed that he would gain unification through "Blood and iron" which meant war and industry. The Franco-Prussian war was a dispute over who would become the king of Spain, leading to a united Germany which won a quick decisive victory. All the German states joined north German confederation to form a German Empire. .
One example of nationalism leading to the division of an empire was the Ottoman Empire. There was a great deal of diversity throughout the empire. People couldn't relate to each other because they had no common traits. There was a great sense of nationalism by the Young Turks. They attempted to overthrow the sultan and turned against all Christians, leading to genocide, or the attempt to kill and entire religious or ethnic group.