The "prompt and utter destruction" clause has been interpreted as a veiled warning about American possession of the atomic bomb (which had been tested successfully on the first day of the conference). On the other hand, the declaration also made specific references to the devastation that had been wrought upon Germany in the closing stages of the European war. To contemporary readers on both sides who were not yet aware of the atomic bomb's existence, it was easy to interpret the conclusion of the declaration simply as a threat to bring similar destruction upon Japan using conventional weapons.