Correction: A previous version of this obituary misstated Dr. Steinbruner’s age. He was 73. This version has been corrected.

John D. Steinbruner in an undated photo. (Courtesy of Brookings Institution)

John D. Steinbruner, an influential author and scholar who advised political leaders and oversaw foreign policy, security and international studies at the Brookings Institution in Washington and later at the University of Maryland, died April 16 at his home in the District. He was 73.

The cause was multiple myeloma, said his wife, Cris G. Steinbruner.

Dr. Steinbruner taught political science at the Massachusetts Institute of Technology and Yale University and public policy at Harvard University’s Kennedy School of Government before joining Brookings, where he directed the foreign policy studies program from 1978 to 1996.

He helped write or edit dozens of books, articles and monographs on subjects including international alliances, defense strategies, the Cold War, arms reductions and Soviet-era foreign policy. One of his books was written with two future secretaries of defense: William J. Perry and Ashton B. Carter.

During the latter half of the Cold War, Dr. Steinbruner was deeply concerned that error or misjudgment could lead to nuclear disaster. His work called attention to the perils of nuclear weapons that could be launched within minutes, and he studied the dynamics of decision-making under duress and in times of crisis.

When the Reagan administration was preparing its first re­armament plans in 1981, Dr. Steinbruner weighed in with an article in Foreign Policy magazine that was prescient and revelatory, pointing out that the nation had a major vulnerability in the­ command-and-control systems that would handle any decision-making in a nuclear attack.

“The United States does not have a strategic command system that could survive deliberate attack of a sort the Soviet Union could readily undertake,” he wrote.

He worried about “confusion, miscalculation, failure of coordination” and possible consequences of such vulnerabilities in the crucible of a nuclear crisis.

After the Cold War, Dr. Steinbruner was one of a handful of specialists who helped alert then-Sen. Sam Nunn (D-Ga.), chairman of the powerful Armed Services Committee, about the urgent need to address the dangers posed by the collapse of the Soviet nuclear, chemical and biological weapons systems.

Dr. Steinbruner was at a key meeting in Nunn’s office in November 1991 with the senator and Perry, then working at Stanford University, and Carter, then at Harvard. They were brought together by David Hamburg, then the president of the Carnegie Corp. of New York. The discussion gave rise to the Nunn-Lugar legislation, sponsored by Nunn and then-Sen. Richard G. Lugar (R-Ind.) to deal with the threat of loose nukes and other dangers in the shadow of the Soviet implosion.

Dr. Steinbruner played an important role in launching an effort to deal with Russian biological weapons in the 1990s.More recently, he was concerned with the dangers of climate change and cyberconflict.

In a 1991 Brookings Institution report written with William W. Kaufmann, who was an MIT political scientist and defense expert, Dr. Steinbruner argued that after the collapse of the Soviet Union and the end of the Cold War, the United States could cut military spending by one-third over the following decade.

That could yield savings of $300 billion to $600 billion, the report said, and the United States could still have the military strength to meet any foreseeable military challenge.

In the post-Cold War years, the two authors predicted, U.S. security “will depend as much on its moral authority, diplomatic skills and economic assets as on its military capabilities.”

Dr. Steinbruner left Brookings in 1999 for U-Md., where he was a professor of public policy and directed the Center for International and Security Studies. At both institutions, he mentored a generation of scholars who went on to become prominent in arms control and other security matters.

John David Steinbruner was born on July 12, 1941, in Denver. He graduated from Stanford University in 1963 and received a doctorate in political science from MIT in 1968.

Restrained, disciplined and courtly in his dealings with professional colleagues, Dr. Steinbruner projected a different persona at play. On the tennis court, he “let loose and played aggressively,” Brookings colleague Michael E. O’Hanlon recalled.

He also had an intense sense of personal integrity, O’Hanlon said. If he took an afternoon off to hike in the woods while attending an out-of-town conference, he always saw to it that the time was charged to his vacation allowance, not to Brookings, O’Hanlon said.

His first marriage, to Maureen Strain, ended in divorce. Survivors include his wife of 26 years, Cris Gobin Steinbruner of Washington; two sons from his first marriage, David Steinbruner of Colorado Springs and Gregory Steinbruner of Brooklyn; a stepdaughter, Gretchen Gobin of Washington; as well as five grandchild­ren.

In 2011, after a professional lifetime of scholarly writing, Dr. Steinbruner wrote his first novel, “The Secular Monastery,” which was self-published. The story was about a professor who is asked by the president to investigate what appears to be a terrorist attack on a government laboratory that was using a smallpox virus in controversial experiments.

He was on vacation on the Outer Banks of North Carolina, “on his third or fourth bout with multiple myeloma,” when he started writing the novel, his wife said.

“He just decided to try something new from scholarly writing,” she said.

David Hoffman is a former foreign editor and former assistant managing editor for foreign news at The Washington Post.