1954: Did the Eisenhower administration really offer to drop atomic bombs on the Vietminh troops besieging the French at Dien Bien Phu? Nine years after Hiroshima and Nagasaki, did the Americans contemplate once again using their nuclear arsenal in combat? Howard Simpson thought so. “The relevant documents remain classified,” he wrote in Dien Bien Phu: The Epic Battle America Forgot, “but enough has seeped out through personal comments and written memoirs to suggest that such a proposal was seriously considered.” Fortunately for the men on the ground, the idea was abandoned; any attack would have wiped out attackers and defenders indiscriminately.
Source: Martin Windrow, The Last Valley: Dien Bien Phu and the French Defeat in Vietnam (2004), pp. 568–9