西史 - Triple Alliance 和 Triple Entente 如何引發 WW1?

第一次世界大戰（簡稱一次大戰、一戰、歐戰；1914年8月─1918年11月）是一場主要發生在歐洲但波及到全世界的世界大戰。當時世界上大多數國家都捲入了這場戰爭。

戰爭過程主要是同盟國（德語：Mittelmächte）和協約國（法語：Entente）之間的戰鬥。 德意志帝國、奧匈帝國屬同盟國陣營，英國、法國、俄羅斯帝國、塞爾維亞和義大利則屬協約國陣營。在1914年至1918年期間，很多在亞洲、歐洲和美洲的國家都加入了協約國。戰場主要在歐洲。值得注意的是義大利雖是德國和奧匈帝國戰前的同盟，但是後來英國、法國及俄國與義大利簽訂密約，承諾給予義大利某些土地，結果義大利加入了協約國對抗同盟國。

這場戰爭是歐洲歷史上破壞性最強的戰爭之一。大約有6,500萬人參戰，1,000萬左右的人失去了生命，2,000萬左右的人受傷。並且造成了世界嚴重的經濟損失,據估計損失了1700億美元。

戰爭的導火索是1914年6月的塞拉耶佛事件，戰線主要分為東線（俄國對德奧作戰），西線（英法對德作戰）和南線1（又稱巴爾幹戰線）（塞爾維亞對奧匈帝國作戰）。其中西線最慘烈，著名的戰役有馬恩河戰役，凡爾登戰役和索姆河戰役。

World War I (WWI, the First World War), also known as the Great War and "The War to End All Wars", was a global military conflict that took place primarily in Europe between 1914 and November 1918 but officially ended with the Treaty of Versailles in June 1919. It left millions dead and re-shaped the modern world.

The war was fought between the Allied Powers (France, the Russian Empire, the British Empire, and later Italy and the United States) and the Central Powers (Austria-Hungary, the German Empire, Bulgaria and the Ottoman Empire). The Allies would prove victorious over the Central Powers, but resentment over the defeat and the controversial Versailles treaty, particularly in Germany, would become a major factor contributing to World War II.

Much of the fighting in World War I took place along the Western Front, within a system of opposing manned trenches and fortifications (separated by an unoccupied space between the trenches called "no man's land") running from the North Sea to the border of Switzerland. On the Eastern Front, the vast eastern plains and limited rail network prevented a trench warfare stalemate from developing, although the scale of the conflict was just as large. Hostilities also occurred on and under the sea and — for the first time — from the air. More than nine million soldiers died on the various battlefields, and millions more civilians perished.

The war caused the disintegration of four empires: the Austro-Hungarian, German, Ottoman, and Russian. Germany lost its overseas empire, and new states such as Czechoslovakia, Estonia, Finland, Latvia and Yugoslavia were created, or in the cases of Lithuania and Poland, recreated.

World War I created a decisive break with the old world order that had emerged after the Napoleonic Wars, which was modified by the mid-19th century’s nationalistic revolutions. The outcome of World War I was a major cause of World War II twenty-one years later.