Which agency manages and executes intelligence operations during peacetime, crisis, and war?

The Defense Intelligence Agency (DIA) is the correct choice as it is specifically tasked with managing and executing intelligence operations for the United States during peacetime, times of crisis, and wartime. The DIA gathers, analyzes, and disseminates military-related intelligence to support national defense and military planning. Its focus on defense-oriented intelligence makes it essential for understanding and addressing threats to national security across different phases of military engagement.

In contrast, the Central Intelligence Agency primarily deals with civilian intelligence needs and international matters rather than military-specific operations. The Federal Bureau of Investigation focuses on domestic law enforcement and counterintelligence rather than overt military operations. The National Security Agency specializes in signals intelligence and information assurance but does not engage in the same comprehensive military intelligence role as the DIA. This distinction underscores why the Defense Intelligence Agency is the correct answer, given its particular mandate and operational focus.