Intelligence and Counterintelligence Summary

  • Last updated on November 11, 2022

Simply put, intelligence (or “intel”) is information that has been processed, evaluated, and analyzed.


Simply put, intelligence (or “intel”) is information that has been processed, evaluated, and analyzed. Intelligence exists to support policy makers and military leaders in a variety of ways. Basically, intelligence is concerned with issues related to national security and is normally collected and processed in secret. Counterintelligence (CI) is the effort made by intelligence organizations to prevent foreign intelligence services from gaining information about them or disrupting their activities. CI efforts are also directed at preventing other intelligence services from conducting espionage within a nation’s borders. The military also conducts CI in order to carry out protective measures at home and among units deployed abroad.Intelligence gatheringCounterintelligenceEspionageIntelligence gatheringCounterintelligenceEspionage


The role of intelligence and the agencies that conduct intelligence activities can be broken down into four primary components. The first is to prevent a potential enemy from achieving strategic surprise. Second is to provide policy makers with knowledge that has been collected and assessed by experts, usually over a long period of time. This is especially important in governments where the leadership is transitory. The third role is to support the policy-making process. Decision makers require current intelligence in order to determine what policies they may wish to carry out. Timely intelligence can offer critical background information, help determine risk, and enable leaders to consider the potential risks and rewards of the decisions they are considering. Finally, there is the need to keep secret the methods of collecting intelligence as well as the information needs of decision makers. Governments and the military need to keep some information secret from others and, at the same time, have ways of getting information from those who wish to keep their knowledge confidential. This makes having intelligence services vital, for both civilian and military organizations.

History of Intelligence and CounterintelligenceAncient World

The importance of good intelligence has been understood throughout history. The ancients of the Middle East, the Egypt;intelligence gatheringEgyptians in particular, had sophisticated intelligence organizations. The Egyptians were among the earliest to employ codes, specialized inks, and other methods for communicating secretly in writing, for example. Other ancients in the Middle East also carried out intelligence activities. According to the Bible, the Hebrews;intelligence gatheringHebrews relied on the use of spies as they entered the Promised Land.

The Greece;intelligence gatheringGreeks and Romans relied heavily on intelligence to govern and defend their respective civilizations. The story of the Trojan horseTrojan horse is a classic example of the use of deception to defeat an enemy. The Greek city-states routinely spied on one another, seeking intelligence about military strength and defensive capabilities. The Rome;intelligence gatheringRomans were very dependent on intelligence, especially after the creation of the empire. Rome routinely conducted espionage activities against its neighbors in order to gauge their respective strengths and weaknesses. Agents also were used to try to induce potential enemies to ally themselves with Rome. Counterintelligence activities had more of a political connotation as rival factions within the government often plotted against one another.

The legendary ancient Chinese general Art of War, The (Sunzi) SunziSunzi (Sun Tzu) commented on the importance of learning about one’s enemies and the use of spies to gather intelligence. Writing in Sunzi Bingfa (c. fifth-third century b.c.e. ; The Art of War, 1910), Sunzi outlined methods for establishing espionage networks and for the recruitment of defectors. KauṭilyaKauṭilya (Indian philosopher)[Kautilya] Kauṭilya (also known as Cāṇakya or Chanakya, fl. 300 b.c.e. ), in ancient India, also noted the value of intelligence gathering. During the feudal period in Japan, Ninjas ninjas often served as spies for samurai warlords. In general, however, intelligence processes were at the mercy of the skills and the interests of individual rulers.

Medieval World

The fall of the Roman Empire and the onset of the Middle Ages meant that intelligence was focused primarily on military operations or on keeping an eye on one’s vassals. To what degree Feudalism;intelligence gatheringfeudal lords engaged in intelligence activities is difficult to say, as there are no surviving records of such endeavors. The only real full-time intelligence community to come into being in the Middle Ages was created by the Roman Catholic Church. The onset of the Crusades;intelligence gatheringCrusades led the Church to engage in a variety of intelligence operations including spying, sabotage, and even rescue missions to free prisoners of war. At the same time, the increase of religious fervor sparked by the Crusades led to the InquisitionInquisition, which could be thought of as a counterintelligence effort directed against heretics and dissenters. Domestic spying was a vital part of the Inquisition; secret police forces were used by the Church and the Spanish monarchy to root out Heresyheresy and Political dissentpolitical dissent.

As nation-states began to emerge, intelligence began to take on a greater level of organization. Machiavelli, NiccolòMachiavelli, NiccolòNiccolò Machiavelli wrote of the importance of intelligence to rulers who wished to protect their power. Ivan IVIvan IV (the Terrible)[Ivan 04]Ivan the Terrible (Ivan IV) created Russia’s first secret police system in the sixteenth century. In England, Queen Elizabeth IElizabeth I (queen of England)[Elizabeth 01]Elizabeth I relied on the skills of Sir Walsingham, FrancisWalsingham, FrancisFrancis Walsingham to provide her with intelligence. Referred to as the Queen’s “spymaster,” Walsingham was one of the first to utilize intelligence methods in a modern sense. He developed an organization that collected intelligence throughout Europe, penetrated the Spanish military, and used counterintelligence methods to defend Elizabeth from domestic plots. The intelligence community created by Walsingham is noteworthy for its reliance on academics, linguists, scientists, engineers, and other experts for both the gathering and the analysis of intelligence. During the Thirty Years’ War (1618-1648);espionageThirty Years’ War (1618-1648), the Richelieu, Cardinal deRichelieu, Cardinal deCardinal de Richelieu in France played an important role in the establishment of French intelligence. He used domestic spies judiciously in order to defend the monarchy from potential enemies, and his spies abroad not only provided intelligence culled from other European monarchs but also worked to deceive them with false information.

Modern World

Intelligence began to take on forms that are more recognizable in today’s world. A series of revolutions and wars from the seventeenth through the nineteenth century led to an increasing appreciation of intelligence and counterintelligence and the use of clandestine and covert operations. Washington, GeorgeWashington, GeorgeGeorge Washington was especially aware of the importance of good intelligence, and he worked diligently to learn about the intentions of the British during the American Revolution (1775-1783);espionageAmerican Revolution (1775-1783). Washington proved to be a most capable spymaster: He successfully organized and supervised spy rings, recruited agents, organized deceit and deception operations, helped develop the codes and disappearing inks his spies used, and even served as his own intelligence analyst. Washington fully understood the importance of secrecy in intelligence operations in order for them to be successful. Later, as president, he oversaw the intelligence activities of the United States–the first American president to do so–and thereby established the precedent of executive control of the intelligence function.

A diplomat named Wickham, WilliamWickham, WilliamWilliam Wickham (1761-1840) oversaw British intelligence efforts against France during the French Revolution (1789-1793);espionageFrench Revolution (1789-1793) and Napoleonic Wars (1793-1815);espionageNapoleonic Wars (1793-1815). Operating from his diplomatic post in Switzerland, Wickham organized spy rings and supported operations designed to restore the French monarchy. Although these attempts failed, Wickham continued to operate spy rings that provided the British with key information about French military activities until the French learned of his spying and got the Swiss to have him removed from his post. British agents also carried out several unsuccessful attempts to assassinate Napoleon Bonaparte during his reign as emperor. Intelligence was equally important to the French. Counterintelligence was carried out by Fouché, JosephFouché, JosephJoseph Fouché, who had enemy agents discredited or killed. Napoleon INapoleon I (Bonaparte)[Napoleon 01]Napoleon also oversaw intelligence operations, supervising spies and organizing operations designed to deceive enemy commanders. Likewise, under the direction of Prince Metternich, Klemens vonMetternich, Klemens vonKlemens von Metternich, Austria developed an effective intelligence organization to keep tabs on domestic and foreign threats. By the 1850’s, Prussia;espionagePrussia was relying on its secret police to guard that nation’s national security, and later it used espionage to help prepare for German unification. The use of an extensive network of spies was a major factor in the German defeat of France in the Franco-Prussian War (1870-1871)[Franco Prussian War];espionageFranco-Prussian War (1870-1871).

The decoding of the so-called Zimmermann note, an intercepted German telegram that proposed an alliance of Germany, Mexico, and Japan against the United States, led the Americans to declare war on Germany on April 6, 1917.

(AP/Wide World Photos)

Intelligence played a vital role in the American Civil War (1861-1865);espionageAmerican Civil War (1861-1865). Both the North and the South utilized spies, but new technologies also began to revolutionize intelligence activities. Both sides made use of Balloonsballoons in order to conduct aerial reconnaissance. The Telegraphtelegraph not only allowed for speedier communications but also led to more sophisticated encryption and code-breaking efforts. False messages were often transmitted from captured telegraph stations. Both sides even tapped each other’s telegraph lines. Information was acquired not only from spies but also from prisoners of war, documents taken from the battlefield dead, and newspapers.

Prior to the outbreak of hostilities World War I (1914-1918)[World War 01];espionagein 1914, Germany had undertaken massive spying efforts in France and Great Britain. German spies sought to obtain military secrets as well as confidential political and industrial information. In addition to its espionage activities during World War I, Germany also conducted sabotage operations not only against its opponents but also against neutral nations, such as the United States.

The British responded to reports and rumors of German espionage by creating the Secret Service Bureau (Great Britain)Secret Service Bureau to counter the German intelligence-gathering efforts. By the eve of World War I, the British Secret Service had largely broken up Germany’s spy rings, and it continued to identify and apprehend enemy agents during the war. Counterintelligence efforts also were directed at protecting vital ports, factories, and warehouses from enemy saboteurs. In the United States, the responsibilities of the Federal Bureau of InvestigationFederal Bureau of Investigation (FBI) were expanded to include counterintelligence activities. Both sides relied heavily on encryption and code-breaking techniques for intelligence and counterintelligence purposes. The interception and decoding of the Zimmermann note“Zimmermann note” by the British was a significant counterintelligence victory that contributed to the entrance of the United States into the war.

Technological advances, particularly in communications, made the need for accurate intelligence, delivered quickly, a necessity for all of the belligerents. Equally important was counterintelligence. The outcome of battles was often the result of good intelligence or counterintelligence. In the secret war of intelligence, the Allies won a decisive victory over the Axis powers. The Ultra projectUltra project, for example, enabled the British to decipher German codes and contributed to the successful defense of Great Britain against the German air offensive of 1940, and to the defeat of Rommel, ErwinRommel, ErwinErwin Rommel and his German forces in Africa. The ability of the U.S. Navy to break Japan’s naval codes led to an American victory at the Midway, Battle of (1942)Battle of Midway (1942). The Allies were able to perform successful deceit and deception operations against the Germans, and a variety of covert operations were carried out by the British Special Operations Executive (Great Britain)Special Operations Executive (SOE) and the American Office of Strategic ServicesOffice of Strategic Services (OSS). Aerial reconnaissanceAerial reconnaissance came into increasing use as well. Although the Axis powers conducted numerous intelligence activities as well, their efforts were not as successful as those of the Allies.

There were failures, however. The successful Japanese attack at Pearl Harbor attack (1941)Pearl Harbor was the result of a massive intelligence failure on the part of the United States. Information was not shared between intelligence offices, and American analysts assumed that the disparity in strength between the two nations would keep the Japanese from risking war with the United States. In addition, the war-making capabilities of the Japanese were seriously underestimated. Finally, despite their alliance with both countries, Soviet spies penetrated the British and American atomic bomb projects.

Prior to World War II, the United States had no real intelligence organization to speak of. The Japanese bombing of Pearl Harbor on December 7, 1941, had demonstrated the need for a structured intelligence function within the government, and this led to the establishment of the Central Intelligence AgencyCentral Intelligence Agency (CIA) in 1947. The United States was the last of the world’s major powers to create a national intelligence agency, and the CIA quickly took up its role in gathering foreign intelligence and conducting covert and clandestine activities abroad. Other major intelligence agencies included the Soviet Komitet Gosudarstvennoi Bezopasnosti (Soviet Union)Komitet Gosudarstvennoi Bezopasnosti (Committee of State Security, or KGB), Britain’s MI6[M I six]MI6, China;intelligenceCentral Department of Social Affairs (China)China’s Central Department of Social Affairs (now the Ministry of State Security (China)Ministry of State Security), and Israel’s Mossad (Israel)Mossad.

Decades Cold War (1945-1991);espionageof distrust between the United States and the Soviet Union and the destruction of the Balance of powerbalance-of-power system in World War II helped bring about conflict between the United States and the Soviet Union. The Cold War would result in a great deal of intelligence activity between the United States and the Soviet Union, along with their respective allies. The competition for intelligence between the two sides was intense. Massive espionage networks sought to gather intelligence and engaged in counterintelligence operations against each other. The Soviets tended to rely more on Human intelligencehuman intelligence (HUMINT), or spies, for acquiring intelligence, while the United States emphasized technology to a greater degree. The establishment of the National Security AgencyNational Security Agency in 1952 and its mission of collecting foreign Signals intelligencesignals intelligence (SIGINT) and cryptanalysis reflected the American focus on technology as a primary collection resource.

Aerial Aerial reconnaissancereconnaissance, such as U-2 spy planesU-2 and SR-71 spy planes[SR seventy one]SR-71 overflights of the Soviet Union and other nations, provided the United States with critical information about their missile and nuclear capabilities, and both sides eventually used orbiting satellites to monitor compliance with nuclear and arms reductions treaties, movements of military units, and the general state of affairs within other nations, as well as for intercepting communications. Spies such as Rosenberg, JuliusRosenberg, JuliusJulius and Rosenberg, EthelRosenberg, EthelEthel Rosenberg, Ames, AldrichAmes, AldrichAldrich Ames, and Hanssen, RobertHanssen, RobertRobert Hanssen in the United States, and Philby, KimPhilby, KimKim Philby and Fuchs, KlausFuchs, KlausKlaus Fuchs in Great Britain, turned over atomic and other secrets to the Soviet Union, while Soviet military officers such as Penkovsky, OlegPenkovsky, OlegOleg Penkovsky and Popov, PyotrPopov, PyotrPyotr Popov provided British and American intelligence with vital information about Soviet military and intelligence capabilities and operations.

The end of the Terrorism;intelligenceCold War brought new challenges for intelligence agencies, particularly the rise of international terrorism. The penetration of terrorist cells is difficult for a variety of reasons, not least of which is that members of terrorist organizations are known to one another or have contacts who can vouch for them. Therefore intelligence agencies often rely heavily on a variety of other techniques, including SIGINT, Imagery intelligenceimagery intelligence (IMINT), and financial research and analysis, to monitor terrorist organizations and apprehend their members.

Besides terrorism, nations face other threats to their security, and they will continue to seek out intelligence about the intentions and capabilities of enemies, potential enemies, and even friendly nations. In addition, border security issues, internal dissent, competition for natural resources, the proliferation of weapons of mass destruction, the resurgence of piracy, and numerous other regional and global issues will make intelligence a vital function of governments for a long time to come.Intelligence gatheringCounterintelligenceEspionage

Books and Articles
  • Andrew, Christopher, and Vasili Mitrokhin. The Sword and the Shield: The Mitrokhin Archive and the Secret History of the KGB. New York: Basic Books, 2000. Presents the story of what The Washington Post called “one of the most extraordinary events in the intelligence game since the Soviet Union collapsed,” KGB espionage activities, based on the archives of KGB researcher and defector Vasili Mitrokhin.
  • _______. The World Was Going Our Way: The KGB and the Battle for the Third World. New York: Basic Books, 2000. This volume is the second installment of the history of postwar espionage based on the Mitrokhin archive, secret KGB documents through which the late coauthor revealed the Soviet Union’s activities in Africa, Asia, and Latin America. Photographs.
  • Black, Ian, and Benny Morris. Israel’s Secret Wars: A History of Israel’s Intelligence Services. New York: Grove Press, 1992. Designed for specialists and spy buffs, a history of five decades of Israeli intelligence, from internal conflicts to victories in spying on Arab neighbors.
  • Dorril, Stephen. MI6: Inside the Covert World of Her Majesty’s Secret Service. New York: Free Press, 2002. A history of Her Majesty’s secret service that debunks myths and reveals a more fumbling organization than legend would suggest. Documents activities conducted for the United States as well as various assassination plans and spy operations.
  • Knightley, Philip. The Second Oldest Profession: Spies and Spying in the Twentieth Century. New York: W. W. Norton, 1980. A history of spies and spying, from the first modern intelligence agency, established in 1909, to the present day, with emphasis on Britain, France, Germany, Russia, and the United States. Knightley is unsympathetic to elaborate espionage operations, considering them expensive and corrupting.
  • Lowenthal, Mark W. Intelligence: From Secrets to Policy. 4th ed. Washington, D.C.: CQ Press, 2009. A primer on intelligence (including boldfaced key terms, reference lists, and useful appendixes) that considers both the history of intelligence gathering and the impact of intelligence institutions on public policy decisions.
  • Richelson, Jeffrey T. A Century of Spies: Intelligence in the Twentieth Century. New York: Oxford University Press, 1997. Written by a senior fellow at the National Security Archive, this volume examines both technological and human intelligence and their impact on history, decade by decade: from Adolf Hitler through the Cold War to economic espionage.
  • Volkman, Ernest. The History of Espionage. London: Carlton Books, 2007. An investigative reporter and former executive editor of Espionage magazine provides an overview of spying from ancient times to the world after the terrorist attacks of September 11, 2001.
  • Weiner, Tim. Legacy of Ashes: The History of the CIA. New York: Doubleday, 2007. A Pulitzer Prize-winning New York Times correspondent uses archives and interviews with CIA insiders (such as former chiefs Richard Helms and Stansfield Turner) for this history of the agency. Weiner argues that the CIA has, in the main, done more damage than good when it became distracted by gadgetry and covert actions under presidential influence while neglecting its mission to provide accurate intelligence.
  • Wise, David. Nightmover: How Aldrich Ames Sold the CIA to the KGB for $4.6 Million. New York: HarperCollins, 1995. Wise, an acclaimed espionage expert, rehearses the Ames case and the mole-hunt team that brought him to justice. The damage inflicted achieves a human dimension as Wise tells the tragic stories of the CIA operatives whom Ames identified.



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