Four nations have already been discussed: Germany, Austria-Hungary, Russia and Serbia. Other nations became involved because of existing treaties and colonization.
France Declares War with Germany
Because of nationalistic attitudes and feelings of animosity toward Germany, in accordance with their treaty with Russia and beause Germany declared war on France, France declared war on Germany on Monday, 3 August 1914. Most of the major battles were fought on French soil. Even though France was on the winning team, she suffered a great deal of destruction. Farmland, factories, many small villages and some large cities were damaged or completely destroyed and tens of thousands of her citizens killed or wounded.
Italy Changes Sides
The 1882 Triple Alliance between Germany, Austria-Hungary and Italy brought Italy into the war as an ally of Germany. Initially, Italy declared neutrality. Austria-Hungary was not pleased with this and diplomatic relations with Italy soon deteriorated. Finally, on 23 May 1915, the relationship with Austria-Hungary broke down completely. Italy then declared war on Austria-Hungary and joined the Allies. Though they were not prepared for a major war, Italy did send over one million troops into battle.
The Ottoman Empire Joins In
In a successful diplomatic move German signed the Ottoman Empire (current day Turkey) into a secret agreement (signed on 2 August 1914). The empire was concerned about Russian interference in the Dardanelles. An alliance with Germany would protect their shipping interests. To assist the Empire, on 10 August Germany sent two war ships, the Goeben and the Breslau to the Empire. Technically, the ships were sold to the Empire, but the German crews and officers remained onboard.
On 29-30 October, the Goeben led several Turkish ships to attack Odessa and several other Russian ports in the Mediterranean Ocean.
Bulgaria had been a vassal state of the Ottoman Empire until they declared independence in 1913. The Empire saw the war as a means to get Bulgaria back under their control.
The Empire engaged in military actions in support of Germany. This created an additional front in the Balkans and North Africa. The Turkish armyâ€™s offensives in North Africa were in the Saini Desert against both English and Russian troops. These conflicts, though rather extensive, did not go well for the Empire. Even though they were unsuccessful, they were supportive of the German Command. British and Russian troops prevented the Empire from taking control of the Saini. This kept them in that area rather than being freed to transfer to the combat zones of Western Front in Europe.
On the decline during the late 19th century, the Ottoman Empire collapsed completely after World War I. After its decline over thirrty countries were either created or freed. Among them were Syria, Crimea, Egypt, Bosnia, Bulgaria, Jordan, Palestine and the area currently known as the United Arab Emirates.
Portugal is Drawn In
German imperialism extended to colonies in Africa. Portugal also had colonies in North Africa, particularly Mozambique and Angola, and was concerned about a possible German assault on them. She also had received requests from Britain on 7 August 1914, for naval support. The support was granted.
Initially, Portugalâ€™s involvement was only naval, but eventually 55,000 infantry soldiers and 1,000 artillerymen fought in France.
England Enters the Fray
When Germany was preparing to invade France, they asked permission of Belgium and Luxembourg to move troops through those two countries. This would allow them to invade France from the west, thereby bypassing the French forces defending their northern border. Because they were neutral nations, both Belgium and Luxembourg refused their permission. Germany decided to go through them anyway. The treaties of neutrality with Great Britain were immediately invoked.
Great Britainâ€™s involvement included England, Scotland, Wales, Ireland, Australia, New Zealand, South Africa.
The United States Joins In
Under Woodrow Wilson, president of the United States, isolationism prevailed. The war was thousands of miles away and the policy to stay away from other nations problems, held them out of the war for a short period of time. Then German submarines started to sink passenger ships traveling between Britain and the United States. In 1915 a German sub sank the Lusitania. There were 159 American citizens on board.
Also, in 1917, a telegram, now known as the Zimmerman Telegram, was sent by the Germany to Mexico. In it the Germans told the Mexican government that, if they attacked the United States, Germany, when the war ended, would give Mexico United States territories, presumably the lower western states. These probably included California, Nevada, New Mexico and Texas.
The United States declared war on Germany on 6 April 1917, almost three years after the start of hostilities.
Japan Becomes Involved
In 1902 Japan and Britain entered a treaty of mutual support. Japan entered the war because of that agreement. Japan also entertained the possibility of gaining territories in the North Pacific. Should Japan persevere she would get any territories previously held by Germany. When Vienna refused to remove the Austro-Hungarian cruiser SMS Kaiserin Elisabeth from Tsingtao, Japan declared war not only on Austria-Hungary, but also on Germany.
Germany had a small naval coaling port on the China coast at Jiaozhou Bay in the port of Qingdao. In September 1914, the Japanese attacked the base and forced the German fleet to leave the area. The fleet headed south-east toward the western coast of South America.
The Japanese did not stop at Qingdao, but continued to attack other German colonies in the North Pacific, specifically the Marianas, Caroline Islands and Marshal Islands. These colonies were left defenseless when the German fleet left.
Because of extensive colonization by the major nations and the conscripting of colonial men and materials, there were one hundred countries involved with the war: the major fourteen and eighty-six colonies. Colonies belonging to both sides of the conflict existed in Africa, Asia, South Pacific, South America and the Caribbean. In Africa alone there were forty-two colonies. Another twenty-five came from South America and the Caribbean. The remaining nineteen colonies were in Asia, South Pacific and South America.