Summary of Evidence
- U-2 planes were flown over Cuba on August 29, September 6, 17, 26, 29, and October 5 and 7 to survey SAM sites, coastal defense missile sites, MIGs, missile patrol boats, and IL-28 light bombers.
- On September 7 a U-2 plane accidently violated Soviet air space and was chased out by Soviet fighters. Then on September 10 a Chinese Nationalist U-2 plane was shot down over mainland China. To reduce risk U-2 planes would most often peer into Cuba from a 3 km distance.
- Poor weather or cloud coverage sometimes limited the number of U-2 flights that could be performed to as little as twice a month.
- On October 9 a U-2 flight over San Cristobal was attempted, but the plane’s engine lost power and the mission was aborted.
- On October 14 a U-2 plane snapped pictures of medium-range missile transporters, erectors, and launchpads over San Cristobal.
- More U-2 flights were conducted over the following days in order to monitor the missiles’ construction.
- Agents gave several accounts implying Cuban nuclear arms development. They were given consideration but thought to be merely suggestive.
- It usually took agents at least ten days to relay their findings back to Washington.
- An agent reported overhearing Fidel Castro’s personal pilot boasting about Cuba having nuclear arms able to strike the United States.
- A CIA agent reported seeing a 60 foot long trailer in a convoy. An intelligence analyst assumed that the agent had misjudged its size and actually saw a 30 foot long SAM missile.
- The CIA was able to identify the types of missiles that were found in U-2 photography, how soon they would be ready to fire, and their ranges after being provided information by Oleg Penkovsky, a Soviet intelligence agent who defected to America.
- America closely monitored the number, size, physical characteristics, and cargo of Soviet ships sent to Cuba.
- It was through shipping intelligence that the United States first became aware of the Cuban arms build-up.
- The CIA determined that the contents of the shipments included electronic and construction equipment, SAMs, MIGs, patrol boats, and soviet technicians.
- The cargo of some ships was unknown. In fact, shipping intelligence did not lead to the identification of MRBMs or IRBMs.
- Two Soviet ships, the Omsk and the Poltava transported nuclear arms to Cuba. American intelligence noticed they had large hatches and rode high in the water, characteristics expected from a ship transporting nuclear arms. However, this was not considered reliable enough to use as evidence of Cuban nuclear missile development until after the missiles were already identified.
- Many refugees described sightings of missiles or convoys. The accounts of several thousand refugees were collected and analyzed in 1962 by the CIA.
- Their large numbers often resulted in substantial lag. There also sometimes was a significant time gap between the refugee’s sighting and when they came to America.
- The reports were often too imprecise to be of value and even factually incorrect. In fact, modern research suggests that only eight of all of these accounts were accurate.
- The accounts could not be verified at the time so they were not given significant consideration.
- One refugee account accurately described the Remedios site, a building meant to store nuclear warheads. This account came four days after the nuclear warheads were already discovered.
Evaluation of Sources
Purpose: Allison’s purpose in writing this work was to analyze various aspects of the Cuban Missile Crisis and hence explain why it happened the way it did.
Value: This source is quite valuable to this investigation. Allison thoroughly describes the techniques America used to gather intelligence and discusses how successful they each were. Since the author is an expert he may be assumed to be very knowledgeable and hence the information in the source is quite reliable.
Limitations: There are limitations on the value of this source. Allison was alive during the Cold War. He therefore may have a biased perspective that favors America because of his American nationality. The value of this source is further limited by its focus. It does in detail address the topic of this investigation but it focuses on the Cuban Missile Crisis in general rather than this specific topic.
Purpose: Hilsman wrote this book to examine how the CIA and American government went about making decisions during the Cuban Missile Crisis and the effect these had on its outcome.
Value: This source is of great value to this investigation. Hilsman in great depth discuses the methods by which the CIA gathered intelligence and how successful they each were. His personal experience in the CIA during the crisis makes him more knowledgeable and gives him a unique perspective. Furthermore, he is an expert and so the information in this source is likely well researched and reliable.
Limitations: There are significant limitations on this source. Hilsman’s past role in the CIA during the Cuban Missile Crisis may result in his evaluation of the CIA being biased. For instance, he may present America’s intelligence gathering techniques as having been more successful than they actually were. This notion is reinforced by how throughout the work he expresses admiration for the CIA’s accomplishments.
Schaff argues that intelligence agents were paramount to the CIA’s intelligence, Oleg Penkovsky in particular. The knowledge Penkovsky provided allowed for the effective identification and classification of the Cuban missile sites. The U-2 photography would have been of much less value without this contribution. However, Allison believes that intelligence agent reports were in general of much less value than this. He makes reference to how there was a time delay with this intelligence source of around ten days, though this is less than was with the refugee accounts. In contrast, Hilsman suggests that intelligence agents provided helpful information. He describes a number of agent reports which implied Cuban nuclear arms development, such as an agent’s sighting of a 60 foot trailer. Another example of this is the agent who heard the boastings of Castro’s pilot. In contrast, Allison argues that this evidence only seems convincing in hindsight. The reports of intelligence agents were taken more seriously than those of refugees but were still generally considered too uncertain to use as evidence.
Hilsman emphasizes the value of shipping intelligence. He points out that it was through this source that the CIA initially became aware of Cuba’s arms buildup. Furthermore, the type and quantity of most resources being shipped to Cuba could be accurately monitored. However, Allison presents a more critical view. He believed that the value of this intelligence source was diminished by how cargo on some ships could not be identified. For instance, this was the case with nuclear arms. Chang and Kornbluh agree with Allison on this point. They illustrate this by considering the Omsk and the Poltava. Even though there was some evidence that these ships carried nuclear arms the cargo could not be identified and so the shipping intelligence was too uncertain to be conclusive.
Allison believes that aerial reconnaissance was America’s most valuable source of intelligence. He discusses how through this source SAM sites, airplanes, navy, and nuclear arms were detected and actively monitored. Unlike with other sources the information provided by this intelligence was certain and reliable. It was consequently through this that Cuba’s nuclear arms were first identified. Hilsmen agrees with Allison regarding the value of aerial reconnaissance. However, he considers its limitations whereas Allison does not. He describes how the U-2 plane’s dependence on weather was a significant weakness. This greatly reduced the frequency of its flights and hence decreased the amount of information that the U-2 plane could gather. The U-2 plane was also subject to mechanical failure, as seen with the attempted U-2 flight over San Cristobal on October 9. Furthermore, the reduction of the U-2’s surveillance in September to generally staying at least 3 km from Cuba improved safety, but at the cost of reduced surveillance over Cuba’s center.
 Allison, Graham T. Essense of Decision Explaining the Cuban Missile Crisis. Harper Collins Publishers, 1971.
 Chang, Laurence, and Peter Kornbluh. "The Cuban Missile Crisis A Chronology of Events." George Washington University. 1992. http://www.gwu.edu/~nsarchiv/nsa/cuba_mis_cri/590101_620919%20Chronology%201.pdf (accessed October 5, 2011).
4] Frankel, Max. "Learning From the Missile Crisis." Smithsonian, 2002: 52.
 Garthoff, Raymond L. "Foreign Intelligence and the Historiography of the Cold War." Journal of Cold War Studies, 2004: 21-56.
 Philips, Steve. The Cold War Conflict in Europe and Asia. Essex: Pearson Education Limited, 2001.
 Schaff, Marta. "Cuban Missile Crisis." Cuban Missile Crisis, 2009: 1-2.