Mutual defense alliances led to countries such as Russia defending Serbia and Germany protecting Austria-Hungary, contributing to the outbreak of World War I.
Mutual defense alliances created a situation in which Russia was obligated to defend Serbia and Germany was obligated to defend Austria-Hungary. These alliances, such as the Triple Entente and the Triple Alliance, played a significant role in the escalation of World War I as countries were pulled into a web of obligations and conflicts.
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