How did WW1 end?

Contrary to Marxist mythology, the First World War ended not through mutiny or popular uprising, but through decisive military defeat. Certainly, the major combatants were exhausted, and their peoples weary of the war, but the only country voluntarily to withdraw from the war was Bolshevik Russia. 

Germany launched its forces into a huge offensive in France in the spring of 1918, breaking the trench deadlock and threatening Paris. The Allies regrouped, broke the German advance and counter-attacked. On 8 August, at Amiens, Haig inflicted a devastating defeat on the Germans – German general Erich Ludendorff called it the ‘Black Day of the German Army’.

Further heavy defeats followed, and by September both he and Paul von Hindenburg [a senior military figure] were demanding an end to the war. Faced with total defeat, in November the Germans forced the Kaiser to abdicate and declared a republic, which then asked for an armistice. It is difficult to conceive that this would have happened had Germany not been crushed on the battlefield.

Source:

http://www.historyextra.com/feature/first-world-war/how-did-ww1-end