In 1900, the triumph of the national state in Europe seemed almost complete. Responsive and capable of tackling many practical problems, the European nation-state of 1900 was in part the realization of ideologues and patriots like Mazzini and the middle-class liberals active in the unsuccessful revolutions of 1848. Whereas early nationalists had envisioned a Europe of free peoples and international peace, the nationalists of 1900 had been nurtured in the traditional competition between European states and the wars of unification in the 1850s and 1860s. This new generation of nationalists reveled in the strength of their unity, and the nation-state became a system of power.

Thus, after 1870, at the same time the responsive nation-state improved city life and brought social benefits to ordinary people, Europe’s leading countries also projected power throughout the world. In Asia and Africa, the European powers seized territory, fought brutal colonial wars, and built authoritarian empires. Moreover, in Europe itself, the universal faith in nationalism promoted a bitter, almost Darwinian competition between states. Thus European nationalism threatened the very progress and unity it had helped to build. In 1914, the power of unified nation-states would turn on itself, unleashing the First World War.