Why did Brittan fight in World War 1?

Answer 1

Britain had not planned on joining a war between countries on the Continent. It had no military alliances that would force them to aid any nation in a war. Had Germany gone straight into France, Britain may have never declared war or at least waited. But Germany went through Belgium, a country with which England had a defense treaty and good trade relations. In honor of that treaty and to protet that beneficial business, Britain joined the war on August 4, 1914.

Answer 2

Britain entered WWI because it was allied to France at the time the war started. Romantic ideas about warfare also played a role in Britain's entry into WWI, as well as a belief that it was a war that could be quickly and painlessly won.