How did forces of nationalism develop and affect the Middle East region post-WWII?

One of the facts that marked the rise of hostilities between the countries that participated in World War I was nationalism. Created as an identity of peoples during the 19th century, nationalism was used as a means of persuading the popular masses for the expansionist desires of the rulers of Empires and other countries. The discourse of the need for civilian citizens to join the army to defend their nation and country was a resource used as a way to expand the contingent of armies.

In addition, the nationalist discourse served to foster the territorial expansion of some states, a situation that was presented as necessary to unite peoples. In this sense, some great nationalist movements emerged that would influence war.