Did Bismarck’s alliances keep the peace or cause WWI?

The short answer

• A new giant in the middle of Europe. Unification turned a loose group of German states into an empire with the largest population west of Russia and the fastest-growing industry on the continent. Its population rose from about 41 million in 1871 to about 65 million by 1910, while France’s stalled near 39 million, and by 1913 Germany produced more than twice as much steel as Britain. Every other power had to decide how to live beside such a neighbour, and that question, more than any single treaty, set the problem the alliance system tried to solve.
• Alsace-Lorraine and the French grievance. The peace that completed German unity also guaranteed French hostility. The Treaty of Frankfurt took Alsace and most of Lorraine, with about 1.5 million people, and imposed an indemnity of five billion francs, much as a court today orders a losing party to pay damages. France paid the money within three years, but the lost provinces stayed a permanent wound in French politics, so Bismarck’s diplomacy spent twenty years containing a grievance that his own victory had created.
• The Eastern Question. The slow retreat of the Ottoman Empire, the Turkish-ruled state that had governed the Balkans for centuries, left a vacuum that Austria-Hungary and Russia both wanted to fill. Russia saw itself as the protector of the Orthodox Slavs and wanted free passage for its warships through the Straits, while Austria-Hungary feared that strong Slav states on its border would unsettle the Slavs inside its own empire. Diplomats called the problem of who would inherit the Ottoman lands the Eastern Question, and because both rivals were Germany’s partners, every Balkan crisis forced Berlin to choose between them.
• The Kaiser’s new course. The new Kaiser’s determination to rule in person ended Bismarck’s system within two years. Wilhelm II, emperor from 1888 at the age of twenty-nine, forced Bismarck to resign in March 1890. His new chancellor, Leo von Caprivi, and the foreign office adviser Friedrich von Holstein wanted a simpler, more transparent policy, and they judged the Reinsurance Treaty incompatible with the alliance with Austria-Hungary. Their search for clarity cut the hidden link that had kept Russia from looking to Paris, so German policy became easier to read at exactly the moment it became more dangerous.

What it changed

A war plan built on two fronts. Once France and Russia were allied, German planners assumed that any war would be fought in the west and the east at once. Alfred von Schlieffen’s answer, set out by 1905 and put into action in August 1914 (Chapter 4), was to defeat France first with a sweep through Belgium and then turn east before Russia’s slow mobilisation was complete. A violation of Belgian neutrality was therefore built into German strategy years before the crisis that would trigger it.

Britain bound by conversations. The secret Anglo-French staff talks that began in 1906, and the naval arrangements that followed, created an expectation the British cabinet could not easily disown, even though the ententes contained no promise to fight. In August 1914 (Chapter 3) Britain went to war over Belgium, yet its army’s plans to fight beside the French made intervention far easier to imagine. Informal commitments can bind as tightly as treaties once soldiers have planned around them.

A naval race that Germany lost. The fleet that Tirpitz built to win British respect made Britain treat Germany as its most likely enemy, and by 1912 the Royal Navy had concentrated its battleships in the North Sea. When war came (Chapter 8), the German High Seas Fleet was too small to win and too valuable to risk, and it spent most of the war in harbour while a British blockade strangled German trade. The race left Germany with an expensive fleet and no way to use it.

Every crisis becomes a test of loyalty. Because each bloc now feared that a diplomatic defeat would break its alliance apart, every colonial or Balkan quarrel after 1905 became a test of whether partners would stand together. Germany tried to split the Entente at Tangier and failed, and both sides concluded that they must back their partners more firmly next time. That conclusion, traced in Chapter 2, turned three crises in six years into rehearsals for war.