Which command is NOT associated with homeland defense?

USCENTCOM, or United States Central Command, primarily focuses on operations in the Middle East and Central Asia. Its mission is largely centered around promoting stability and security within its area of responsibility, which includes countries such as Iraq and Afghanistan. This is in contrast to homeland defense, which pertains to protecting the territories of the United States from domestic threats.

On the other hand, USNORTHCOM is specifically tasked with overseeing homeland defense operations within North America, including the protection of the U.S. mainland, during times of war and crises. USSOCOM, or United States Special Operations Command, can also play roles that include homeland defense through the use of special operations forces, and USTRANSCOM is responsible for the transportation of military forces and supplies, which can be critical during responses to domestic threats.

Thus, since USCENTCOM's focus is external and does not directly involve homeland defense, it is correctly identified as the command not associated with that mission.