Just seen this. At the time there was no doubt why we'd gone to war, if only because nothing less would have motivated the populace to volunteer in the droves that they did.
We went to war in 1914 because Germany invaded Belgium, and we had treaty obligations guaranteeing Belgian neutrality. In the larger sense, because of the Triple Entente with France and Russia.
If you mean "who started it" it was Austria-Hungary, who'd been itching to deal with Serbia for years.
Just thinking about the Great War gets me angry and upset by turns, anger at the General Staff (on all sides) stuck in the mindset of One Big Push and upset at the waste of life. The French were by far the worst, believing, and founding their war plans on, the élan vital of the French poilu that would ensure their success. Reaching an awful fulfilment with Nivelle's "Ils ne passeront pas!" at Verdun, leading to the tragedy of the Chemin Des Dames, following which the French Army mutinied.
Edited at 2012-11-16 01:24 am (UTC)