How might internal dissent in european states have led to world war i?

European leaders might have diverted attention away from internal dissent and problems by rallying their nations to the cause of war.

The nations of Europe were struggling to adjust to societal changes brought on by industrialization.  There were workers strikes and rising socialist movements that caused internal tensions between the ruling classes and the working class.  In some parts of Europe, such as the Austro-Hungarian Empire, nationalistic fervor by different ethnic groups was causing unrest within their borders also.   Solving a nation's internal problems posed great difficulties.  It was easier to point to other nations as the great threat and problem to their people's security.  It seemed to leaders that "prosecuting an active foreign policy" (as some Austrian leaders put it) was a way to suppress internal domestic troubles.  

Its a whole new world