unintended consequence

Unintended consequences are situations where an action results in an outcome that is not (or not only) what is intended. The unintended results may be foreseen or unforeseen, but they should be the logical or likely results of the action. For example, it is often conjectured that if the Treaty of Versailles had not imposed such harsh conditions on Germany, World War II would not have occurred. From this perspective, the war could be considered an unintended consequence of the Treaty of Versailles.
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