The CIA has been involved in countless CIA operations and controversies from assassination of foreign leaders, overthrow of democratic governments, drug trafficking to fund illegal contras all over the world and many more for which there is simply not enough space to cover here. Some of the more important CIA operations are described here.
In the first years of its existence the CIA was mainly concerned in trying to prevent the spread of communism in Europe. The agency supported anti communist groups in Eastern Europe without much success. The infiltration of anticommunist spies in Belarus and Ukraine also ended in total failure.
The CIA also supported an organization based in Poland with financial and technical aid that was run by the polish intelligence. The agency found more success in limiting the spread of Communism in France and Italy, especially in the Italian elections of 1948.
Also, a network of government organizations in Western Europe called the Gladio network was set up by the CIA. This secret network was used for terrorist attacks in Italy. The violence was blamed on the "Red Brigades" and other Italian Left wing groups. This was called the strategy of tension and was a successful CIA attempt to dishonor the Italian Left.
The OSS recruited many prominent Nazis after the Second World War. This policy was later adapted by the CIA. These included people like Klaus Barbie and General Reinhard Gehlen. Reinhard Gehlens specialty was soviet intelligence and his spy network became Americas chief source of intelligence against USSR. This was the basis of BND the German intelligence agency.
When Europe started to stabilize into communist and noncommunist states in the 1950s, CIA diverted its attention towards developing nations around the world to try and counteract perceived communist threat. In 1953, CIA overthrew the Mossadegh government in Iran. In 1954 CIA overthrew the government in Guatemala. Both countries saw pro American dictators take over the leadership in place of democratically elected goverments.
The CIA was also involved in supporting Suharto of Indonesia and provided him with advanced field communication equipment. This enabled Suharto to coordinate operations more effectively. It is estimated that around 500,000 people were executed during this time, mostly ethnic Chinese.
One of the more controversial of CIA operations are the efforts to overthrow Fidel Castros government. In 1961 the agency organized Bay of Pigs Invasion in Cuba. This operation was a complete failure and a major embarrassment to the CIA. Castro used the event to consolidate his power and strengthened ties with USSR. The CIA run Operation Mongoose was aimed to assassinate Fidel Castro which failed several times.
On the local front, the CIA was involved in a mind control research program called project MKULTRA from 1950s to 1960s.
The CIA faced further controversy when a prosecutor from New Orleans brought to light the relationship between Clay Shaw and CIA in the J.F. Kennedy assassination case. Shaw was alleged to have participated in data collection assignments for the CIA. Shaw denied all allegations. The Assassination Records Review Board indicates that the CIA hid documents regarding its knowledge that someone was impersonating Lee Oswald.
George Tenet presented the Worldwide Attack Matrix on September 15, 2001. It was a top secret document describing CIAs anti terrorism efforts around the globe. These actions would range from "routine propaganda to lethal covert action in preparation for military attacks"