The Vulcan Defense Directorate was an agency within the Vulcan government that was active by the 22nd century. In 2155, T'Pol decided to formally resign from the Defense Directorate and instead devote her time to the United Earth Starfleet. (ENT novel: Beneath the Raptor's Wing)

Presumably, the Vulcan Defense Directorate was in charge of the Vulcan Defense Force but whether it was the same name for the Vulcan Ministry of Defense or a separate body is unknown.
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