Heusinger remained in the army and soon after the outbreak of the Second World War was promoted to colonel and appointed chief of operations at the OKH. When General Kurt Zeitzler became sick in June 1944, Heusinger became temporary army chief of staff and was standing next to Adolf Hitler when the bomb planted by Claus von Stauffenberg exploded on July 20, 1944.
Heusinger, who was slightly injured in the blast, was arrested by the Gestapo and accused of being involved in the July Plot. He appeared before Roland Freisler and his People's Court on August 7, 1944. Although there was evidence that Heusinger had contact with many of the conspirators, he was exonerated, but he was not allowed to return to his senior post in the German Army.
After the war, he played an important role in NATO and was chairman of its military committee (1961-64). Adolf Heusinger died in 1982.