The FBI furnished Oppenheimer's political enemies with evidence that intimated communist ties. These enemies included Strauss, an AEC commissioner who had long harbored resentment against Oppenheimer both for his activity in opposing the hydrogen bomb and for his humiliation of Strauss before Congress some years earlier. Strauss had expressed opposition to exporting radioactive isotopes to other nations, and Oppenheimer had called them "less important than electronic devices but more important than, let us say, vitamins."