Britain was not directly attacked or immediately threatened in July-August 1914. Its decision to go to war was driven by a combination of treaty obligations, strategic interests, and public opinion.
| Factor | Details |
|---|---|
| System of alliances | Europe was divided into two armed camps: the Triple Alliance (Germany, Austria-Hungary, Italy) and the Triple Entente (France, Russia, Britain). Any local conflict risked triggering a European war by pulling in alliance members |
| Assassination of Archduke Franz Ferdinand | 28 June 1914 — heir to the Austro-Hungarian throne killed in Sarajevo by Gavrilo Princip, a Bosnian Serb nationalist. Austria issued ultimatum to Serbia; war escalated by alliance obligations |
| The Schlieffen Plan | Germany's war plan required invading France through neutral Belgium, to knock France out quickly before turning to fight Russia. This meant violating Belgian neutrality |
| Treaty of London 1839 | Britain had guaranteed Belgian neutrality in this treaty. When Germany invaded Belgium on 4 August 1914, Britain had both a legal obligation and a clear moral justification for entering the war. Grey called it defending "a scrap of paper" — but the German foreign minister's dismissive phrase backfired, boosting British public support |
| The arms race | Britain and Germany had been competing to build the largest navy since 1898. Germany's naval expansion threatened British naval supremacy — which Britain's global trade depended on. A German-dominated Europe would be a strategic threat to Britain even without the Belgian treaty |
| Britain declares war | 4 August 1914 — Britain declared war on Germany after Germany invaded Belgium. The ultimatum expired at midnight |
This key facts covers Key Evidence: Britain Goes to War, 1914 within Britain in Peace and War, 1900-1918 for GCSE History. Revise Britain in Peace and War, 1900-1918 in Component Group 3 — British Depth Studies for GCSE History with 14 exam-style questions and 18 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 5 of 17 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Britain in Peace and War, 1900-1918
Describe four features of the wealth and class divide in Edwardian Britain around 1900. [4 marks]
Describe four features of the Liberal reforms introduced between 1906 and 1911. [4 marks]