Why did Britain immediately enter World War I?
1 Answer
The legal Casus Belli was the violation of Belgian Neutrality
Explanation:
The formal/legal cause was the violation of Belgian neutrality by Germany in August 1914, Britain was a guarantor of Belgian independence by a 70 year old treaty
Other causes are still being debated by historians, but here are some of the reasons
The underlying reason was the prospect of an even more powerful Germany occupying the North Sea coast of Belgium and possibly France as well enabling the German Fleet to operate from multiple bases would make blockade far more difficult and effectively hold a "dagger to Britain's throat"
The possibility or eliminating German colonies in Africa
A genuine commitment to Belgian Independance
We had no formal defence agreement with France in 1914 though the Entente had brought the two countries closer