Concern for Germany's growing militarism, Kaiser Wilhelm II's obsession to match Britain's navy and the existence of the long established French and German war-plans only fueled the air of instability in Europe. It was the assassination of Archduke Franz Ferdinand that ignited the global conflict.
1915 was to see warfare take on a new dimension with the bombing of British cities by Zeppelin airships. Germany also began U-Boat attacks on neutral shipping, a policy that would contribute to the United States entering the war. Gas was also used for the first time by the Germans.
In February, the Germans began their assault on the forts at Verdun in a battle of attrition that would last until December. In the East, the Russians launched an offensive to try and relieve the pressure on the French. Although the Russians ultimately failed to make any gains, it did draw German divisions away from the Western Front.
The most catastrophic revolt of all occurred in the Russian Army where hundreds of thousands of soldiers deserted. Russia's Great war was essentially over. Germany moved many more troops to the Western Front and despite America's entry into the war, it would not be until 1918 when the full effect of their involvement would be appreciated.
Using ""Storm Trooper" tactics, the Germans launched attacks against the British with devastating results. In just three weeks, the Allies lost 400,000 men. Completely overwhelmed, General Haig issued his famous "Backs to the Wall" message to the troops. The lack of resources caused by naval blockades and the first appearance of "Spanish Influenza" meant that the German forces halted.