What organization was involved in selecting Robert Gates as secretary of defense?

The selection of Robert Gates as Secretary of Defense was primarily driven by The White House, specifically during the presidency of George W. Bush. The President has the authority to nominate individuals for such key positions, and this nomination requires Senate confirmation to take effect. Gates previously served as the Director of the Central Intelligence Agency (CIA), which may lead to some confusion regarding the influence of that organization, but ultimately, it was the President and his administration that chose Gates to fulfill the role of Secretary of Defense, underscoring the executive branch's power in appointments of this nature.