Most expensive covert action
Operation Cyclone
2,000,000,000 US dollar(s)
Afghanistan ()

The most expensive covert action was Operation Cyclone, the United States Central Intelligence Agency's program to arm and train Islamist insurgent groups (known as "mujahideen") fighting the Soviet Red Army in Afghanistan. Between 1979 and 1989, the CIA channelled more than $2 billion in weapons, logistical support and training to the mujahideen.

Operation Cyclone was the brainchild of President Jimmy Carter's National Security Adviser, Zbigniew Brzezinski. He supported the idea of arming the mujahideen because he believed that it would draw the Soviet Union or its proxies into a drawn-out and inconclusive anti-insurgency campaign (often referred to as "their Vietnam"). In addition to weakening America's primary strategic rival, it was hoped that Operation Cyclone would tie down Soviet military resources that might otherwise be deployed against its increasingly restive Eastern European client states.

This chapter of the CIA's involvement in Afghanistan began on 3 July 1979, when President Jimmy Carter authorised the first tranche of covert aid to the mujahideen. At the time these scattered insurgent groups were fighting against the government of Nur Muhammad Taraki, an Afghan communist and KGB asset who had seized power in a Soviet-backed coup in 1978. This initial authorisation was for $500,000 worth of medical supplies and non-military equipment.

The resources allocated to Afghanistan were dramatically increased following the 24 December 1979 Soviet invasion. The Carter administration lifted its initial restrictions on weapons shipments and raised the budget to tens of million of dollars. Under newly elected president Ronald Reagan, in 1981 the CIA was given a $30 million budget for Afghan operations. By 1984, this budget had risen to $200 million per year. At its peak in 1987, the CIA was working with an annual budget of $700 million to procure equipment and logistical support for the Mujihideen.

In the early years, the CIA sourced equipment from grey-market dealers all over the world. They used proxies to acquire old surplus equipment – such as World-War-II-era British Lee-Enfield rifles – that couldn't be easily traced back to the United States. As the war progressed, however, the CIA made less of an effort to disguise their support of the Mujahideen, using less robust covers for their activities and eventually shipping easily traced US-made FIM-92 Stinger anti-aircraft missiles.

The long term legacy of this program has been highly controversial. Many of its original architects regard it as a success, and it certainly played a role in weakening the Soviet Union and perhaps accelerating its eventual collapse. However, the lack of oversight with which the CIA distributed weapons and military aid led to numerous heavily armed militant Islamist factions being left to battle for power after the Soviet Union withdrew. Many of the figures involved in the US-backed struggle against the Soviet invaders would go on to become notorious terrorist commanders, including Jalaluddin Haqqani (leader of the Haqqani Network), Mohammed Omar (leader of the Taliban), and Osama bin Laden (leader of al-Qaeda).