The article distinguishes the specificity of the US policy towards the South China Sea issue in relations with the Association of Southeast Asian Nations (ASEAN) through the prism of enhancing ASEAN’s role as a “driving force” of multilateral security dialogue in the Asia-Pacific region. The outlines of the American approach to the issue during and after the Cold War are drawn, the influence of the Chinese-American contradictions upon ASEAN’s policy is identified, the consequences of the US reaction on the verdict of the Permanent Court of Arbitration for ASEAN’s role as a “driving force” of the Asia-Pacific multilateral dialogue frameworks are examined, the repercussions of the project of the Indo-Pacific region and its current institutional frame - the Quadrilateral Defense Cooperation - for the further evolution of the South China Sea issue in the US-ASEAN dialogue are presented. Scenarios of the future evolution of ASEAN unity on the South China Sea issue through the lens of the Quad’s further development, prospects for the ASEAN countries to join this format and China’s counter-measures are considered. The findings of the article reveal that in the practical realm the strengthening of ASEAN unity and its positions as a driving force of the Asia-Pacific multilateral security dialogue platforms with the focus on the South China Sea issue has never been a priority task for Washington.