This chapter examines the intersection of intelligence and foreign policy, with a focus on Türkiye’s experiences. It explores how intelligence failures and politicization impact national security and policymaking. Emphasizing the role of time constraints, organizational challenges, and cognitive biases, the analysis highlights the dual nature of politicization: both detrimental and beneficial. Positive politicization, where intelligence supports policy while maintaining impartiality, is crucial for effective foreign policy. Through the lens of Türkiye, the study illustrates how intelligence diplomacy—integrating intelligence insights into diplomatic efforts—can enhance strategic decision-making and contribute foreign policy outcomes.