It can be said that nationalism, aligned with imperialism, led Europe to disaster in 1914, because of the following reasons:
i. By the last quarter of the nineteenth century, nationalism no longer retained its idealistic liberal democratic sentiment of the first half of the century but became a narrow creed with limited ends.
ii. Nationalism aligned with imperialism led Europe to disaster in 1914. But, many countries in the world which were colonised were in a very bad shape.
iii. During the period an intense rivalry among the European powers emerged over trade and colonies as well as naval and military might. This led to a series of wars in the region and final the First World War.