Ideological struggle (World War I)

We are not used to seeing World War One as an ideological struggle, a battle between democracy and autocracy. Yet that is in many respects exactly what it was. The original coalition of course contained Tsarist Russia, but Britain and France had a shared democratic heritage. In 1917, the defeat of Russia and adherence of the USA to the coalition polarised the conflict to one between a group of states committed to liberal and democratic values, and a militarist autocracy. The coalition was imperfectly democratic. Both Britain and France had large colonial empires whose people did not have access to democratic forms of government, and both sought to extend their empires at the expense of their enemies. In Britain, universal male suffrage, along with the vote for some, but not all, adult women, was only introduced at the end of the war. All states behaved in some ways that were at odds with liberal democratic principles, persecuting pacifists for example.
Yet there was a qualitative difference between the democratic powers and Germany. For one thing, 'remobilisation' of the French and British peoples by playing the democratic card helped rally support for the war in 1917-18 whilst, in Germany, support for the regime crumbled. Britain and France came to be led by Lloyd George and Clemenceau, popularist democratic leaders, while Germany was ruled by a military dictatorship that sidelined the constitutional leader, the Kaiser. An Allied victory led to the maintenance and even extension of liberal democracy in Europe. A German victory would have snuffed it out. When the German army appeared to be on the verge of victory in spring 1918, the Kaiser crowed that this was the vindication of monarchy and autocracy over democracy.
http://www.bbc.co.uk/history/worldwars/wwone/origins_04.shtml