Helmut Sonnenfeldt, top adviser to Kissinger, dies at 86

Helmut Sonnenfeldt, the top adviser to former secretary of state Henry Kissinger, has died.

Sonnenfeldt, who was credited with playing a key role in forming the Nixon administration’s policy of detente with the Soviet Union, died on Nov. 18. He was 86. His wife, Marjorie, said he had Alzheimer's disease.

The policy of relaxing tensions between the U.S. and USSR took effect in 1971.

Sonnenfeldt and Kissinger were German-born Jews who fled the country during the Nazi rise to power and met shortly after serving in the U.S. Army in World War II, according to The Washington Post.

“He was with me in practically every negotiation I conducted with the Soviets,” Kissinger reportedly said in an interview, adding that he regarded Sonnenfeldt as an “indispensable associate.