Decolonizing Security in East Asia challenges failing sovereign-centric models in the Indo-Pacific. It identifies a 'postcolonial security dilemma' where states camouflage ontological identity anxieties as existential survival discourse to secure Western recognition. The advocacy for an 'Asian NATO' epitomizes this mimicry, institutionalizing rigid binaries that provoke regional friction and invite the very external interventions they claim to deter. While regional groupings such as ASEAN or BRICS attempt to 'delink' from Western hegemony, they often fall into a 'Sovereign Sensibility Trap.' By hyper-fixating on sovereign equality, they ironically reproduce colonial logic, inviting fragmentation and marginalizing local peace. Moving beyond state-centrism, this Element proposes 'pluriversal coexistence' as a radical alternative. Through subaltern sites and grassroots vignettes, it demonstrates how security is found in relational, nonbinary practices rather than rigid borders. This Element provides a transformative framework for moving beyond the colonial architectures currently fracturing East Asian security.