Having been the defining feature of intra-regional relations in the Middle East since the Egyptian Revolution, the Arab Cold War progressed to the next stage in the early 1960s. Confronted by a rival variant of radical Arab nationalism in revolutionary Iraq and the secession of Syria from the United Arab Republic, Gamal Abd an-Nasir focused his intention on the situation in South Arabia. The struggle against the British position in Aden and the Protectorates became a new rallying point for pan-Arabism. In the aftermath of the overthrow of the Zaidi Imamate in autumn 1962, Nasir quickly decided to militarily support the new republican regime in Sana'a. The ongoing civil war in North Yemen together with the subsequent insurgency against British rule in the South became focal points in the regional Cold War and effected a revirement des alliances in the region. Saudi Arabia ended its accommodationist policies towards the U.A.R. and started a proxy war against Egypt by supporting Yemenite royalists. The insurgents were also supported by the British, Jordan, Iran and, secretly, Israel. The regional Cold War was intensified by parallel Soviet-American competition in the Middle East with the United States attempting to reconcile a rapprochement with the forces of Arab nationalism led by Nasir while at the same time preserving the conservative and pro-Western regime in Saudi-Arabia. Using recently declassified documents from U.S. Presidential Libraries, the U.S. National Archives, the Public Record Office as well as evidence from the former Soviet Bloc, the paper will trace the origins and development of the Arab Cold War in Southern Arabia as well as the involvement of external powers in the conflict. One main aspect of the paper will be the interplay of external and intra-regional forces with the interests and actions of Yemenite actors. It will show how superpower rivalries as well as Anglo-American discord contributed to the failure of several attempts of conflict solution by regional players. Likewise, it will demonstrate how the U.S. (and Soviet) failed attempts to end the proxy wars in the Yemen(s) challenged the existing balance of power in the region and enabled Israeli military activism. The ongoing regional competition led Nasir to re-ignite the Arab-Israeli conflict in order to use the mechanism of the global Cold War in order to transcend the regional Cold War, resulting in major miscalculation and war.