APEC membership makes a strong alliance with Thai economic, therefore, Pushing a proposal in cooperation with APEC, so as a result, Thai's have more weight in a multilateral negotiation framework.
Membership in APEC makes Thailand has a strong economic alliance thereby pushing deals with APEC as a result, Thailand's voice has more weight. Framework for multilateral negotiation
The APEC membership Thailand a strong ally of economic, so to push the proposal with APEC is the resulting sound which have more weight. Multilateral framework for negotiations.