Answer:
Alliances played a significant role in the outbreak of World War I. In the decades leading up to the war, major European powers formed a complex system of alliances and treaties designed to promote their interests and provide for their mutual defense.
The two main alliances that emerged were the Triple Entente, comprising Britain, France, and Russia, and the Triple Alliance, comprising Germany, Austria-Hungary, and Italy. These alliances were formed in response to perceived threats from other powers, and were intended to deter potential aggressors by demonstrating strength and solidarity.
However, the system of alliances also created a situation in which a small conflict between two nations could quickly escalate into a much larger conflict involving multiple nations. This is exactly what happened in 1914, when the assassination of Archduke Franz Ferdinand of Austria-Hungary by a Serbian nationalist led to a chain of events that ultimately drew in all of the major European powers.
In the weeks and months following the assassination, Germany pledged to support Austria-Hungary in its efforts to punish Serbia, while Russia mobilized its army in support of Serbia. France and Britain, both allies of Russia, also began to mobilize their forces. As tensions continued to escalate, Germany declared war on Russia and France, and invaded Belgium as part of its strategy to quickly defeat France.
The outbreak of World War I was thus the result of a complex web of alliances, treaties, and rivalries that had developed over several decades. The system of alliances created a situation in which a small conflict could quickly escalate into a much larger conflict, with catastrophic consequences for the entire world.