In 1917, on this day King Constantine of Greece approves a Declaration of War Against the United States.

King Constantine of Greece Approves Declaration of War Against the United StatesAs the Great War erupted in Europe in 1914, the nation of Greece became caught in the middle. Greece had won its independence in 1830 after nine years of war with the Ottoman Empire, which had ruled the southern Balkans for centuries. The new kingdom grew as Britain returned the Ionian Islands in 1864 and the Ottomans ceded Thessaly in 1881. Further gains were made in the Balkan Wars in the early twentieth century, winning Greek occupation for Macedonia. These wars made great gains for the Balkan League but ended up destroying trust as Serbia and Greece made a secret division of spoils, spurring Bulgaria to declare war against its former allies. Serbians continued to struggle with the Austro-Hungarians, leading to the assassination of Archduke Ferdinand in Sarajevo and the beginning of war over almost all of Europe.

Greece itself became divided. King Constantine, backed by his German wife Queen Sofia, argued for neutrality, which would benefit the Central Powers with free ports to take in supplies for the war effort. Prime Minister Eleftherios Venizelos suggested joining the Entente, noting the necessity of Allied operations in the region against Bulgaria and the Ottoman Empire. If the Greeks did not work with the Allies, he believed they would force cooperation with a blockade by the powerful navies of the British and French, devastating the peninsular kingdom (he noted, "One cannot kick against geography!"). In 1915, the Entente began plans to take the Dardanelles, and Venizelos noted the opportunity to support what he saw as the eventual victors of the war. Constantine refused, causing Venizelos to resign February 21. Elections in August quickly put Venizelos back into office upon the promise of keeping neutrality, but, by October, Venizelos stated that Bulgaria's invasion of Serbia would prompt him to join with the Allies due to their Serbian treaty. An Allied expedition to liberate Serbia arrived at Thessaloniki, causing a final division between the King and Prime Minister.

Constantine determined to use his constitutional power as monarch to dismiss the government and call for new elections. However, reflecting on the division of his peoples and Venizelos' clear popularity, he decided a different action: declaring war on the invading Allies. He arrested Venizelos and many of his supporters, placing them under guard as political prisoners until the nation was secure. The Allied army, which had been divided as the French attempted to march forward alone and were rebuffed by the Bulgarians, was caught and proceeded to retreat. The action doubled the embarrassment of the Allies as it coincided with the failure and evacuation of the Gallipoli Campaign, effectively ending Allied activity in the region. Diplomats in 1916 hurried to prompt Romania into the Entente with promises of immense territorial gains, but heavy losses to Central victories in 1917 forced them out of the war with the Treaty of Bucharest. Russia, too, had fallen due to internal revolution, and the Eastern Front became quiet. Bulgaria worked to relieve its own internal struggles from dissatisfaction among the soldiers fighting a war alongside Muslim Ottomans against fellow Orthodox Christians.

Greece, meanwhile, struggled against the Allied blockade. Cities were bombarded, but shoreline defenses and sabotage proved effective counterattacks. Well-armed resistance fighters made attempts at occupation impossible, turning to bloodbaths akin to Gallipoli. The British Navy was stretched thinly, allowing a good deal of food and materiel to be smuggled between Central nations, relieving much of the tension of the Turnip Winter of 1916-17 from Germany. America came into the war April 6, 1917, and Greece eventually declared war, following the actions of the other Central Powers. By this time, most populations had become disgusted with the war. France had faced mutinies among its soldiers with more than 20,000 soldiers court-martialed. Emperor Charles I of Austria had attempted to sue for peace through secret negotiations shortly before the fall of Russia, causing a diplomatic catastrophe among the Central Powers.

In 1918, the Allies launched aggressive advances along their remaining fronts in France and the Jordan Valley. The Ottoman Empire was clearly crumbling, though the Balkans held in the midst of blockade. In the West, however, German offenses had run out of steam, and Allied counteroffensives pushed back with such force that the end seemed near. Still, they held Eastern Europe, and the decision was made to push through another winter after the Americans had rejected suggestions of an armistice. The Germans were pushed back through Belgium in as organized of a retreat as the German High Command could muster. At sea, convoys and submarine-hunters gradually extinguished the threat of u-boat attack. As another campaign season approached with the spring, German Chancellor Prince Maximilian of Baden finally accepted American President Wilson's Fourteen Points, and the Americans led peace-talks beginning in 1920.

While French diplomats argued vindictively, Germany's delegation stood much of their ground despite losing their overseas colonies. Wilhelm abdicated in favor of his son, Wilhelm III, who had been noted as opposing the war. Austria-Hungary was broken apart along with the Ottoman Empire. The Germans led international intervention into the former Empire of Russia, breaking it asunder as well by granting independence to previous client states such as the Ukraine and stymieing attempts at domination by soviets.

For its part in the war, Greece was mildly punished with reparations that weakened its economy in the long term. Alongside the struggling Greek economy, nationalism expanded as Greeks and Turks fled one another's countries in a population exchange of more than two million. Hardening conservatism battled with socialist ideals, but the King of the Hellenes has maintained a sense of stability in the nation.