Another crisis broke in September 1949 when the Air Force picked up signs of the Soviet Union 's RDS-1 nuclear test. Bacher joined Oppenheimer, Parsons, General Hoyt Vandenberg, the Atomic Energy Commissioners and a British delegation under William Penney to discuss what to do. The recent devaluation of the British pound had already triggered a financial crisis, and there was concern about how the markets would react to the news. Oppenheimer and Bacher saw the evidence of a nuclear test as conclusive, and Bacher in particular came down strongly on the side of making a public announcement, as the number of people who already knew made a leak almost inevitable. Truman made the announcement a few days later.