Option 1 states that Japan was neutral during the First World War. This means that Japan did not take any side and did not actively participate in the war.

Option 2 suggests that Japan fought alongside Germany against the United Kingdom. However, this is incorrect. Japan actually joined the war on the side of the Allies, which included the United Kingdom.

Option 3 suggests that Japan fought against Russia on its own. This is also incorrect. Japan did fight against Russia, but not during World War I. The conflict between Japan and Russia, known as the Russo-Japanese War, occurred in 1904-1905, prior to World War I.

So, option 4 is the correct answer. Japan fought with the United Kingdom against Germany in the First World War.