Told  /  Debunk

Blood on Our Hands

What did Truman and Oppenheimer actually say in that room?

We’ll focus on the following sources:

  • a 1946 memo from Harry Truman to Dean Acheson
  • a 1946 entry in David Lilienthal’s journal
  • Paul Boyer’s book By the Bomb’s Early Light
  • Peter Goodchild’s book J. Robert Oppenheimer (not cited by Bird and Sherwin, but cited by Boyer)
  • Nuel Davis’s Lawrence and Oppenheimer
  • Peter Michelmore’s The Swift Years

After we survey these sources, we’ll address these questions:

  • What did Oppenheimer say and do that irritated Truman?
  • How did Truman react to Oppenheimer in the Oval Office?
  • How did Truman describe the exchange to others afterwards?


Six months after his meeting with Oppenheimer, Truman wrote a memo to Dean Acheson. The context for the memo was that Oppenheimer had written Truman a letter on May 3, 1946, criticizing a proposal to test an atomic bomb on naval installations — testing which was ultimately done at Bikini Atoll in July. Oppenheimer argued that the test was unnecessary, since it was obvious that any ship, if struck by an atomic bomb, would sink. As for the impact of radiation on naval equipment, controlled experiments in a laboratory would reveal far more at much less expense. Finally, Oppenheimer wondered if a “military test of atomic weapons” was wise “at a time when our plans for effectively eliminating from national armaments are in their earliest beginnings.” In other words, the naval testing undermined his goal to demilitarize and internationally regulate nuclear energy.

Truman forwarded the letter to Acheson and attached a memo — the earliest account we have of the Truman-Oppenheimer meeting. He wrote:

Attached is a letter from a “cry baby” scientist, which I wish you would read and discuss with me.
Mr. Byrnes placed him on the Commission to attend the Atomic Bomb tests. He came in my office some five or six months ago and spent most of his time ringing [sic] his hands and telling me they had blood on them because of the discovery of atomic energy.

In Truman’s account, Oppenheimer wrung his hands and said there was blood on them. This is the core of the story as it has been passed down — after all, in Acheson’s 1969 account, he used the same phrase about Oppenheimer “wringing his hands.” However, in the memo, Truman did not share his immediate response to Oppenheimer — what he said to the physicist in the moment. All we have is his reaction some six months later, calling him a “cry baby” in a memo to his Under Secretary of State.