A primary manager and producer of intelligence for the U.S. Department of Defense that was established in 1961 and is located in the Pentagon in Washington, D.C. This agency’s purpose is to provide current, unbiased military intelligence to policymakers and war fighters and to bring the Defense Intelligence Community up-to-date on major issues such as the number of deployed forces, critical assessments, policy, and resources. The DIA also plays a key function in providing intelligence on weapon systems belonging to foreign states. Further Reading. Defense Intelligence Agency (DIA). This is DIA. [Online, May 14, 2004.] DIA Website. http://www.dia.mil.