► Regional cooperation in East Asia has become a challenge due to democratic backsliding, eventually undermining the regional efforts to advance institutional mechanisms for cooperation among states.

► As the institutional foundation for regional cooperation draw on various internal and external factors, any significant change in these factors easily leads to fatal effects in East Asia by altering relations abruptly.

► While democratic backsliding is on the rise worldwide, the East Asia region has witnessed an unambiguous retreat of democratic norms and practices in the past decade. Such democracy retreats made a regional political landscape less amenable to cooperation. 

► Innovative institutional frameworks and redefinition of the roles of both internal-external actors would warrant the improvement of regional cooperation in East Asia.