Archduke Francis Ferdinand, Austria-successor Hungary's to the throne, was killed at Sarajevo, Bosnia. This act of political violence triggered a crisis that culminated in the start of a European war that grew into a global struggle involving various colonies of European imperial powers and the United States of America. The First World War, sometimes known as the Great War, saw enormous loss of life and property devastation.

The war was the defining event of the twentieth century, sparking revolutions first in Russia and then in Germany and Austria. The Ottoman Empire would also be destroyed. From then till now, a large semicircle of lands stretching from Germany in central Europe to Eastern Europe has existed.

From then till now, the huge semicircle of territories beginning in Germany in central Europe, traveling through eastern Europe and the Balkans into Turkey, and then through northern Africa into the Arab peninsula has seen dramatic upheavals in political power and political philosophies.

Furthermore, the highly defective peace treaty that concluded World War I sowed the seeds of continued European international tension, economic disruption, and violence.

That solution dealt harshly with Germany, albeit perhaps no harsher than Germany would have dealt with her opponents if it had won.

Despite the harshness of the settlement with Germany, the new international system failed to offer practical and effective protections against a vindictive return to power.

The United States' scornful disengagement from international politics further eroded the basis for maintaining the peace on which Britain and France relied.

The economic ramifications of the peace treaty created internal economic crises, which aided radical political groups seeking to undo the post–World War I peace treaty.

The domestic instability among subject nationalities on the continent, as well as the imperial rivalry among the major powers that arose in the decades after Germany's and Italy's unification, sparked the First World War, which resulted in these widespread and ongoing harmful consequences. The brutality of the fight was a result of European nations' modern weapons, made attainable by the second Industrial Revolution.

Because of the empires established by European powers in the nineteenth century and the United States' ascension to great power status, the war reached a global scale. Bismarck continued to direct German politics until 1890.

After 1871, he stated unequivocally that Germany was a contented power that desired no additional territorial gains, and he meant it. He want to avert a new battle that would ruin his accomplishment. He attempted to appease French hostility by maintaining diplomatic relations and backing French colonial ambitions.

He also planned for the worst-case scenario. If France could not be reconciled, it had no choice but to be alone. Bismarck aimed to avoid an alliance between France and any other European state, particularly Austria or Russia, from threatening Germany with war.

In 1873, Bismarck made his first move by establishing the Three Emperors' League. The League brought together Germany's, Austria's, and Russia's three major conservative empires.

The league was quickly disbanded because to Austro-Russian competition in the Balkans, which occurred as a result of the Russo-Turkish War, which erupted in 1877. The Ottoman Empire was held together primarily because European nations couldn't agree on how to split it. Serbia and Montenegro were motivated by Ottoman weakness to come to the rescue of their fellow Slavs in Bosnia and Herzegovina when they rose against Turkish control. The uprising quickly extended to Bulgaria.

Then Russia entered the conflict, escalating the situation into a massive international crisis. The Russians wanted to continue their customary agenda of expansion at the cost of the Ottomans.

The Russians wanted to continue their customary policy of expansion at the cost of the Ottomans, and especially to gain control of Constantinople and the Dardanelles.

Russian engagement also mirrored the Pan-Slavic movement, which wanted to unify all Slavic peoples, including those under Austrian or Ottoman domination, under the protection of Holy Mother Russia. The Ottoman Empire was soon obliged to file a peace treaty.

The Treaty of San Stefano, signed in March 1878, was a Russian victory. The Balkan Slavic republics were liberated from Ottoman authority, and Russia received land and a significant monetary compensation.

The agreement, on the other hand, frightened the other big countries. Austria was concerned about the Slavic triumph and the rise of Russian power in the Balkans.

The expansion of Russian hegemony in the Balkans would endanger Russia's own Balkan regions.

The British were concerned about the impact of Russia's triumph on Europe's balance of power as well as the likelihood of Russian control of the Dardanelles. Bismarck could overlook the Balkans for the time being, but he couldn't ignore the rupture in his eastern alliance structure. In 1879, having alienated Russia, he signed a secret contract with Austria. This Dual Alliance said that if Russia invaded either Germany or Austria, they would come to each other's rescue. If another country attacked one of them, they each vowed to remain impartial.

The pact was valid for five years and was renewed on a regular basis until 1918. As the foundation of German culture,

It was condemned at the time as the anchor of German strategy, and some consider it an error in retrospect. It looked to link Germany's fortunes to those of the struggling Austro-Hungarian Empire, borrowing problems for Germany. That is, Germany was far more likely to be pulled into assisting Austria-Hungary than the other way around. Furthermore, by isolating the Russians, the Dual Alliance drove them to seek Western partnerships.

Bismarck was well aware of the threats, but he dismissed them for good cause. He, for one, never let the alliance pull Germany into Austria's Balkan squabbles. As he put it, every alliance has a horse and a rider, and Germany was the rider. He accomplished it.

He made it plain to the Austrians that the alliance was strictly defensive, and that Germany would never participate in an assault on Russia. "Balkan questions can never be a reason for war for us," he remarked.

Bismarck felt that a monarchical, reactionary Russia would not seek an alliance with either a republican, revolutionary France or a more democratic Britain. In reality, he expected the Austro-German talks would scare Russia into pursuing deeper ties with Germany, and he was correct. By 1881, he had strengthened the Three Emperors' League. The three powers agreed to preserve friendly neutrality if any of them were attacked by a fourth power.

Other conditions included Austria's ability to annex Bosnia and Herzegovina anytime it pleased, as well as its backing.