“…The second classification deals with the multilateralism of Indonesia and Australia in security cooperation using the concept of trilateral cooperation (Kelton, M. & David W., 2019), security regionalism (Mcdougall, 2001), security cooperation (Zimmerman, E., 2014), and cyber cooperation (Gultom, Supriyadi, & Kustana, 2018). Several concepts explain each country's self-interest, encouraging foreign policy to increase regional cooperation relationships.…”