In the late 1950s and early 1960s, the member-states of the North Atlantic Treaty Organization (NATO) debated whether a counterforce capability of hundreds of mobile medium-range ballistic missiles (MRBMs) under joint command in Europe was needed to reinforce U.S. extended nuclear deterrence. The conventional wisdom about this issue, echoing the official U.S. government position, has long been that deterrence was robust even without a joint missile force. According to this argument, U.S. policymakers tried to reassure NATO allies, particularly the West Germans, that sharing control of strategic nuclear weapons was unnecessary and unwise. The analysis presented here shows that the problem was not so straightforward. Many officials in NATO countries, particularly in the Federal Republic of Germany (FRG), viewed the MRBM debate not so much as a problem of nuclear weapons control but as a question of extended deterrence credibility and strategic stability, posing an all-or-nothing challenge to NATO.