When the Great War broke out in August 1914, Russia and France were lined up against Germany and Austria-Hungary. Each of these countries belonged to an alliance that committed them to supporting their alliance partner.
Britain was not committed to joining in the war in 1914, but did so. One of the reasons was the Treaty of London of 1839. This treaty committed Britain to protecting Belgium. But was Britain really protecting Belgium or was Britain protecting itself?
You will probably find it helpful to study the Background before you start looking at the sources.
Use the Worksheet as you look through the sources.