The spectre of Vietnam did, inevitably, haunt American participation in the Multinational Force (MNF) in Lebanon. The powers at Geneva, recognizing the dispersal of forces and the tenuousness of communications links in the field, allowed for a graduated ceasefire in Vietnam. The factor of non-obligated parties proved as debilitating a weakness for the MNF in Beirut as it had been for the International Commission for Supervision and Control (ICSC) in Vietnam. MNF-I had at least functioned with the tacit acquiescence of several armed elements, obtained prior to its constitution. The MNF in Beirut did not face an anomaly comparable to South Vietnam's relationship with the ICSC. The Vietnam experience offers confirmation of a related principle as well: that no international peacekeeping body can successfully oppose the self-defined vital interests of a superpower. In Vietnam, the overriding concern was to terminate the French Indochina war of 1946-1954 more than to avert a future war.