What is the process of gathering sensitive information called?

The process of gathering sensitive information is best described by the term "Intelligence Collection Tradecraft." This encompasses the techniques, methods, and practices used by intelligence officers or agencies to collect data, whether through human sources, signals intelligence, imagery intelligence, or open sources. The focus is on systematic, planned operations that aim to acquire valuable information that could impact national security or strategic decision-making.

The other options represent different concepts: National Defense Information refers to any information that could harm national security if disclosed, and Covert Operations involve secret actions or missions typically for strategic or intelligence purposes, rather than the information gathering process itself. Spear-Phishing is a specific type of cyberattack aimed at individuals to obtain sensitive information, but it is not a systematic method of intelligence gathering like Intelligence Collection Tradecraft.