NEW CASTLE, N.H. - JUNE 26, 2011: W.R. Smyser, former U.S. diplomat to Germany and author of "From Yalta to Berlin" at his home in New Castle, N.H. (Tsar Fedorsky)

W.R. Smyser, a historian of modern Germany who also served as a Foreign Service officer, member of Henry Kissinger’s National Security Council staff and deputy high commissioner for refugees at the United Nations, died March 20 at a rehabilitation center in Bethesda, Md. He was 86.

The cause was complications of congestive heart failure, said his wife, Sally Smyser.

Germany exerted a magnetic pull on Dr. Smyser, who spent time in the country as a young man, served there in the Army, held diplomatic postings in Berlin and Bonn, and eventually wrote one of the first comprehensive accounts of its political evolution after World War II — “From Yalta to Berlin: The Cold War Struggle Over Germany” (1999).

“The evolution of Germany into a unified, stable nation, more pacific, liberal and attentive to civil liberties than most even in Western Europe, is a momentous achievement,” the Economist wrote in a review. “Smyser has produced an authoritative, readable account which should become a standard text.”

William Richard Smyser was born in Vienna on Nov. 17, 1931. His father was a Foreign Service officer, whose job caused Dick (as Dr. Smyser was known) to spend his childhood in various European cities, including Berlin. The family moved to Elkins Park, Pa., after World War II.

Dr. Smyser graduated from the University of Pennsylvania in 1952 with a bachelor’s degree in economics. He later received master’s degrees in public administration and government, from Harvard and Georgetown universities, respectively, and in 1976 received a doctorate in political science from George Washington University.

He served in the Army and was stationed in Munich after college, and in 1954 joined the Foreign Service. His first posting was in Algiers, amid the country’s war for independence from France.

In the early 1960s Dr. Smyser served as a special assistant to Gen. Lucius D. Clay, who advised President John F. Kennedy on a showdown against Soviet forces in Berlin. Clay had previously orchestrated the massive Berlin airlift in the late 1940s.

“Clay was the right man in the right place at the right time — twice,” Dr. Smyser told Newsday in 1999. He later chronicled his personal involvement in the Berlin Crisis, as the standoff became known, in the 2009 book “Kennedy and the Berlin Wall: ‘A Hell of a Lot Better Than a War.’ ”

Dr. Smyser held a Foreign Service posting in Saigon, and in 1969 served as a member of the U.S. delegation at the Paris talks to end the Vietnam War. With Kissinger, who was then the national security adviser to President Richard M. Nixon, he traveled on a secret trip to Beijing in 1971; their meeting with Zhou Enlai, the Chinese premier, paved the way for Nixon’s historic visit to China the following year.

Dr. Smyser was political counselor at the U.S. Embassy in Bonn and went on to direct what was then the State Department’s Bureau of Refu­gee Programs. From 1981 to 1986, he was deputy high commissioner for refugees at the United Nations, where he helped coordinate international relief efforts for refugees from Ethi­o­pia and Laos, among other countries.

He later administered the Hilton Humanitarian Prize, which was created by the Conrad N. Hilton Foundation in 1995 and offered a $1 million prize to “the nongovernmental organization judged to have made the most significant contribution to ease the impact or root out the causes of human suffering.”

He wrote 10 books and taught at Georgetown and the Foreign Service Institute.

Survivors include his wife of 49 years, the former Sally Horner of Washington; two sisters; and a brother. A son, Cameron Horner Smyser, died in 1998.

Correction: A previous version of this obituary incorrectly referred to the foundation that created the Hilton Humanitarian Prize. It is the Conrad N. Hilton Foundation, not the Conrad H. Hilton Foundation. The story has been revised.