Advising governments on security, coordinating intelligence or sensitive or secret data or information gathering of government departments and the military services, and correlating, evaluating and distributing intelligence to government agencies. Associated with this role are open and covert activities which protect national security.
Intelligence gathering has always been a function of government. Sun Tsu, the 4th Century BC military writer, devotes one of thirteen chapters on warfare to secret agents.
Accurate political, social and military information is essential for conducting international policy and negotiation between governments. It is not possible to obtain all the necessary information through official sources and channels.
Intelligence organizations tend to take international policy and diplomacy out of the democratic process.