Leonard H. Perroots, an Air Force lieutenant general who directed the Defense Intelligence Agency from 1985 to 1988 and helped oversee efforts to locate Vietnam War servicemen who were still missing in action a decade after the conflict ended, died Jan. 29 at a hospital in Woodbridge, Va. He was 83.

The cause was complications from Parkinson’s disease, said a son, Len Perroots Jr.

Gen. Perroots shaped Air Force intelligence-gathering efforts for three decades during the Cold War, including a stint in Vietnam. In 1983, helped avert a potential nuclear confrontation while serving as deputy chief of staff for intelligence at the Air Forces’s European command in West Germany.

At the time, a NATO military training operation known as Able Archer 83 placed U.S.-Soviet relations “on a hair trigger,” according to a top-secret U.S. intelligence report that was declassified in 2015.

Soviet leaders believed the annual training exercise — involving plans for a potential nuclear strike — to be maneuvers for a surprise attack against Warsaw Pact countries and began deploying nuclear weapons to their launch sites, according to a New York Times analysis of the report.

In the face of Soviet military escalation, Gen. Perroots made the “fortuitous, if ill-informed” decision not to respond, the report said. It added that he and other officers “acted correctly out of instinct, not informed guidance, for in the years leading up to Able Archer they had received no guidance as to the possible significance of apparent changes in Soviet military and political thinking.”

In 1985, Gen. Perroots served briefly as assistant chief of staff for intelligence at Air Force headquarters in Washington and was commander of the Air Force’s intelligence service before being named director of the Defense Intelligence Agency.

As director, he was the country’s highest-ranking military intelligence officer, responsible for an agency that he once characterized not as a “cloak and daggers” spy agency but as a high-powered research group. On his watch, the agency tracked the movements of Soviet forces in Afghanistan and provided intelligence to the Iraqi military in that country’s 1980s conflict with a mutual enemy, Iran.

The agency also increased its focus on international terrorism — in part because of the 1985 hijackings of the Italian cruise ship Achille Lauro by Palestinian militants and of TWA Flight 847 by Lebanese extremists.

In addition, the DIA expanded its efforts to search for the more than 2,000 servicemen who were unaccounted for in the aftermath of the Vietnam War, which ended in 1975.

After a cross-agency effort to locate missing servicemen in Vietnam and Southeast Asia, Gen. Perroots ultimately concluded to The Washington Post in 1992 that “there was no American being held against his will.”

Gen. Perroots retired from the Air Force in 1989 and, for several years, was president of Vector Microwave Research, which purchased missiles and other weapons for U.S. intelligence agencies.

The Alexandria, Va.-based company, which reportedly worked as a middleman for the CIA and the military, was raided in 1997 by U.S. Customs Service and Navy investigators as part of a probe into the company’s transactions, which included missile purchases from China and North Korea. Gen. Perroots was not accused of wrongdoing. Vector shuttered in 1998.

The son of an Italian-born stonemason, Leonard Harry Perroots was born in Morgantown, W.Va., on April 24, 1933. He played baseball and served in the Air Force ROTC at West Virginia University. He graduated in 1955 with a history degree and joined the Air Force three years later. He received a master’s degree in international affairs from George Washington University in 1975.

Survivors include his wife of 64 years, Mary Slavensky Perroots of Lake Ridge, Va.; five children, Sharon Knotts of Clifton, Va., Len Perroots Jr. of San Jose, Steve Perroots of Germantown, Md., Barbara Young of Chalfont, Pa., and John Perroots of Woodbridge; 16 grandchildren; and five great-grandchildren.

A former resident of Manassas, Va., Gen. Perroots most recently had been living at a retirement community in Lake Ridge, Va. His military honors included the Distinguished Service Medal, three awards of the Legion of Merit and the Bronze Star Medal.

At the DIA, Gen. Perroots was privy to many of the country’s most closely-held secrets, but he said that among his most worrisome assignments was his search for missing soldiers believed to be in Vietnam.

“I used to lie awake at night and say to myself, ‘What else can I do?’ ” he told The Post in 1992, adding that he “was willing to consider a clandestine rescue operation” if credible evidence pointed to any imprisoned Americans.

Not content to lead a rescue mission from afar, he said, “I would have jumped in an airplane myself.”