In 1963, the “shuttle diplomacy” efforts of Ellsworth Bunker and Ralph Bunche between Riyadh, Cairo, and Sana’a led to an agreement for the withdrawal of Egyptian and Saudi intervention in the Yemen Civil War. The UN Yemen Observer Mission, which ran from 1963 to 1964, was given the responsibility to oversee this withdrawal. Contemporary and historic perceptions of UNYOM have been tainted by a clash of personalities between the mission leader, Carl von Horn, who embodied the old European leadership of the UN, and Secretary General U Thant, who represented the new Asia-Africa bloc in the UN. UNYOM has been portrayed as the first failure in a new era of “tin-cup peacekeeping” that could scarcely feed and supply UN personnel. The reality, gleaned from interviews in addition to newly available UN and Canadian archives, is starkly different. The mission was in fact a success, limited only by the global conflict that overshadowed UNYOM.