During the 2017 ASEAN Summits all four former members rejoined in negotiations to revive the quadrilateral alliance . In November 2017 Japanese , Indian , Australian and American officials met to continue security cooperation ahead of the ASEAN and East Asia Summits . The meeting included discussion of China 's increased prominence in the South China Sea , and may have signaled U.S. president Trump 's interest in reviving a formal Quadrilateral
2017 ASEAN Summits
2017 ASEAN Summits
Quadrilateral Security Dialogue