When he war broke out, few people had any idea what form the fighting at sea would take. The world's navies were dominated by technologies so new that they'd never been tested under fire. The British public expected a second Trafalgar - but within the first days of the war, German submarines turned the North Sea into a no-go area for Britain's great battleships.
The British responded with strategy of their own: a blockade of Europe to starve the enemy out. Germany took reprisals by launching submarine attacks against civilian ships, including the tragic loss of the Lusitania. Germany dodged the blockade by sending a cargo submarine all the way to America, to pick up essential war materials.
America acted as arsenal and banker to the warring nations but, though targeted by spies and saboteurs, was deeply reluctant to join in. The balance was finally tipped by top secret British code-breakers who deciphered the Zimmermann Telegram which revealed that Germany was encouraging Mexico to attack America. To the Allies' relief, America joined the First World War.
