Mr. Resor, a decorated Army veteran of World War II, was a corporate lawyer in New York and registered Republican when he joined the Johnson administration in 1965. He was recruited by his former Yale classmate, Cyrus Vance, who was serving as deputy defense secretary.
By the time Mr. Resor resigned in 1971, he had been the longest-serving Army secretary since the civilian position was created in 1947.
President Lyndon B. Johnson named Mr. Resor under-secretary of the Army in March 1965 and promoted him to secretary the following July. He inherited a military branch in the midst of a rapid escalation of forces in Vietnam. As Army secretary, Mr. Resor had overall responsibility for the soldiers’ welfare and handled administrative issues related to managing the growing force.
It was a tumultuous time for the Army. Drug abuse, racial discrimination and low morale seeped through the ranks, according to news accounts.
Mr. Resor was known for his quiet efficiency while dealing with such problems. He rarely gave interviews to the press and, according to the New York Times, held only two news conferences.
He was compelled to speak out in 1969 after a group of Army Special Forces soldiers were charged with murder and conspiracy in Vietnam.
The case involved Thai Khac Chuyen, a Vietnamese man who worked on top-secret missions with the Green Berets and the CIA, according to Time magazine. Once the soldiers discovered Chuyen was a double agent and aiding the enemy, he was drugged, interrogated and then shot to death. His weighted body was dumped into the South China Sea and never recovered.
Mr. Resor had approved putting the soldiers on trial but, according to the New York Times, was pressured to dismiss the charges against them at the behest of President Richard M. Nixon and CIA officials.
A few months later, Mr. Resor was called to testify on Capitol Hill after reports surfaced that an Army unit had killed unarmed civilians in the hamlet of My Lai on March 16, 1968.
On the orders of Army 1st Lt. William Calley — he told his men to “waste ’em” — American soldiers killed 109 unarmed civilians. Huts were torched to the ground. Many of the dead were peasant women and their babies.
Mr. Resor told lawmakers that the truth about what had happened at My Lai took more than a year to reach his desk. In the aftermath, Mr. Resor appointed Lt. Gen. William Peers to investigate the massacre. It was later revealed that Army officers had attempted to cover up the killings.
Seymour Hersh, the journalist who won the Pulitzer Prize in 1970 for breaking the My Lai story, said in an interview that Mr. Resor “did the right thing.”
“Give the Army credit — they did a better job than the national press corps and were already investigating the massacre,” Hersh said. “He did a very honorable job, but it was a terrible stain on the Army.”
Calley was convicted of murder and sent to prison. Mr. Resor later censured the commanding officers of the Army division responsible for the killings and had the commander, Maj. Gen. Samuel Koster, reduced one rank to brigadier general.
After resigning as Army secretary, Mr. Resor served as the U.S. delegate to negotiations on military-force reductions in Europe. He briefly was under-secretary of defense during the Carter administration before retiring from government service in 1979.
Stanley Burnet Resor Jr. was born Dec. 5, 1917, in New York. His father was the president of the J. Walter Thompson advertising agency. As a teenager, the younger Resor changed his name to Stanley Rogers Resor.
He graduated from Yale University in 1939. During World War II, he served as an Army officer and participated in the Battle of the Bulge and was wounded in the siege of Bastogne.
He received the Silver Star Medal — the military’s third-highest award for valor — for action outside Neustadt, Germany, in March 1945. Discovering that his commanding officer had become a casualty, Mr. Resor braved “hostile fire, assumed command and reorganized his men to successfully overcome furious enemy resistance,” according to his citation.
After graduating from Yale Law School in 1946, he joined the New York firm Debevoise, Plimpton, Lyons and Gates. He returned there upon leaving the government and retired in 1991.
In 1942, Mr. Resor married Jane Pillsbury, a daughter of the former Pillsbury company chairman John S. Pillsbury. Two Naval officers in pristine white uniforms — Vance and John F. Kennedy — attended their wedding. She died in 1994.
Survivors include his second wife, whom he married in 1999, Louise Mead Resor, of Washington; seven sons from his first marriage, Stanley R. Resor Jr. of Greenwich, Conn., Thomas Resor of Deadham, Mass., Edmund Resor of New York, James Resor of Chevy Chase and Charles Resor, John Resor, and William Resor, all of Wilson, Wyo.; a sister; 20 grandchildren; and two great-grandchildren.