[2] As USD-I, Vickers, who was appointed by President Barack Obama in 2010, was the Defense Department's top civilian military intelligence official.

While in the CIA, he played a key role in the arming of the Islamic mujahideen against the communist government in the service of America's proxy war against Soviet Union influence in Afghanistan.

He was assigned to 10th Special Forces Group (Airborne) at Fort Devens after graduating from SFQC, serving as a senior weapons sergeant from June 1974 to December 1976.

He was a combatives instructor at the United States Military Academy, deployed on a Flintlock exercise, and was attached to Detachment A, Berlin Brigade where he received advanced urban unconventional warfare training.

[6][11] After attending Officer Candidate School, Vickers was commissioned in December 1978 and assigned to 3rd Battalion, 7th Special Forces Group (Airborne) at Fort Gulick in Panama.

He was promoted to captain in September 1982 and commanded a classified counterterrorism (CT) unit for two years in support of CONPLAN 0300, deploying to several Latin American countries, and was a planner for special-operations forces (SOF) contingency operations against the Sandinista regime in Nicaragua.

[6] Regarding ISIS and Al-Qaeda, Vickers advocated a policy of disruption, raids intended to distract and keep militants off-balance such that they are unable to organize and execute action against the United States and its forces in Afghanistan, Iraq, and the Middle East.

[18] In May 2023, The New York Times reported that no evidence has emerged the laptop contained Russian disinformation, and portions of its contents have been verified as authentic, prompting House Republicans to term the signers of the letter, including Vickers, as "spies who lie".

[21][22] Vickers was previously married to Phebe Novakovic, a former intelligence officer, General Dynamics CEO, and director at JP Morgan.