Countries often cooperate and share intelligence for reasons of cost, expertise, or shared security interests. In rare or hypothetical cases, however, a country may enter long-term arrangements in which a foreign government effectively controls or carries out core national intelligence functions on behalf of the dependent country. Core national intelligence functions include collecting intelligence, analysing sensitive security information, or producing threat assessments that shape security or foreign policy decisions. This is distinct from routine information sharing, multilateral intelligence alliances, or short-term joint operations.