In 1882 Italy was added to an already existing alliance between the German Empire and the Austria-Hungary Empire. This was a defensive military alliance where the countries involved promised mutual support in the event of an attack by any other places
In 1907 Russia, France, and Britain signed an agreement to balance the Triple Alliance. When war broke out all three members of the Entente entered the war as allies against Germany and Austria-Hungary.
The Russian war machine moved quickly, pushing into Austria, the Ottoman Empire, AND Germany held Poland. Russian forces were able to capture parts of Austria and the northern part of the Ottoman Empire. However, Germany was able to halt the Russian advance by pulling troops off of the western front.
In order for Germany to overrun France quickly they needed to avoid the fortifications in the east. This required the conquest of neutral Belgium.
As expected, Britain entered the war against Germany and the rest of the world saw Germany as a huge aggressor in the war. The Germans were surprised at the resistance they faced but were still able to stomp their way through the country.
Although Germany was slowed in Belgium they were still able to get within 30 miles of Paris before the combined forces of Britain and France stopped them. Over the next few months the Allied forces pushed Germany back to the French border where both sides dig in and Built trenches.
The Germans were met at the Marne by British and French forces and driven back. Both sides then outflanked each other on their way to the English Channel. This was known as the race to the sea. This completed what would become known as the western front lines.
France and Britain were able to push the Germans back and they held the lines just inside the French border. France planned to push the German army all the way back to the Rhine and take back that area of Germany that used to belong to the French.
Russia was mostly able to maintain the front with only minor losses in the west. However, they made gains in the south against the Ottoman Empire. Over the next year Russian popular opinion turned against the war.
In early 1915 Germany declared a submarine blockade on Great Britain. Germany made it clear that they would fire on any ship approaching Great Britain. Their U-boat technology was the best in the world at the time and underwater control of the seas belonged to Germany. This blockade was meant to dissuade countries from aiding the Allies by sending supplies.
The concept of Total War means that nothing is off limits.
Germany began conducting a series of bombing raids on London to weaken popular support for the war. These occurred about twice a month. Some zeppelins were shot down but they generally flew too high for planes. Their navigation was primitive however and so only about 10% of bombs dropped actually hit their targets.
On May 7th, 1915 a ship bound for England from the United States was sunk by a German U-boat. On board were roughly 1,200 civilians, including 128 Americans. All of them died. This angers the United States and Germany, not wanting the U.S. to enter the war, stops sinking ships without warning.
By 1917 Czar Nicholas II resigns office due to pressure from the people and Russia is thrown into political anarchy.
The communists take charge and, as promised, they sign an armistice with Germany and pull out of the war.
As a result of their surrender, Russia gave Germany many of its western holdings and Ukraine. They also gave back all the territory taken from the Ottoman Empire.
The Battle of the Somme was the 3rd bloodiest battle of all time. This five month offensive was preceded by heavy artillery shelling of the German lines. Many Germans survived the bombardment and the French and British forces had to push hard. By the end of November the Allies had only taken about 6 miles of territory. Over a million lives were lost during this offensive. The Battle of the Somme was also the first appearance of a tank in battle.
Woodrow Wilson was reelected President of the United States using the campaign slogan "he kept us out of the war." American public sentiment was favorable to Great Britain and France, but they still were not ready to get involved in a war that they considered to be a European problem.
By the time the U.S. received the telegram Mexico had already seen it and had rejected the proposal for several reasons:
1: War against a much stronger opponent.
2: Empty promises for financial and arms support from Germany.
3: Would never be able to hold on to the territory if they could take it in the first place.
Arthur Zimmerman was Secretary of foreign Affairs for Germany. Germany's plans to bring back unrestricted submarine warfare worried them because they did not want the neutral U.S. to enter the war but considered it an eventuality. Germany was proactive and sent a telegram to Mexico urging them to go to war with the U.S. in return for U.S. lands if a victory was achieved.
American response was predictable. They did not want to go to war and at first they believed the telegram to be a forgery. In March Zimmerman admitted the telegram, which angered the U.S. population and they demanded a declaration of war.
British intelligence intercepted the telegram and translated it. They wanted to release it to the United States but they were worried that the U.S. would think that is was a forgery. They also didn't want the Germans to know that they could break German code. They waited three weeks before handing the telegram over to the United states.
Although Germany was able to pull nearly 1 million troops from the eastern front to help in the war against the Allies, they wanted to win the war before the Americans landed. In March they started a series of 5 determined offensives which gained them much ground and got them within shelling distance of Paris.
By may the Germans are set to take Paris but the assistance of American troops stops the German advance. The quick German advance had spread their lines too thin which allowed for the allied forces to rout the Germans in retreat.
Germans bound for the western front deserted in huge numbers and by September, allied forces break through the German trenches in northern France. The Kaiser of Germany abdicates the throne on November 9th. On November 11th an armistice agreement is signed and at 11:00, the war is officially over