Answer:
They thought they were unfair.
Shatter belt is a concept in geopolitics according to which on the political map are recognized and analyzed strategically positioned and oriented regions that are deeply internally divided and encompassed in the competition between the great powers in the geostrategic areas and spheres.
The correct answer is Austria-Hungary
Nationalism started rising after numerous years of wars during the 19th century. Austria-Hungary believed that it had the right to be the great empire that it used to be and that it partially was at the moment. That's why things like world war 1 happened since countries wanted to establish themselves as great.