In 2008, the Thai-Cambodian conflict over the Preah Vihear Temple was reignited after the issue became politicized by political groups in Thailand. The opposition accused the Samak Sundaravej government of aspiring to achieve its private interests in exchange for Thailand’s support for Cambodia’s bid to have the Preah Vihear listed as a UNESCO World Heritage Site. In Thailand, there was a belief that if Cambodia’s bid was successful, the country would lose the disputed 4.6-square-kilometer area surrounding the temple. This pushed elements in Thailand to unofficially declare a state of war with Cambodia. This crisis also had a serious impact on ASEAN. Thailand rejected ASEAN’s mediating role, thus revealing its distrust in regional dispute settlement mechanisms. For ASEAN, it unveiled its weakness in exercising authority over its members, and its incompetency in the management of regional disputes. This article argues that ASEAN was caught between the need to be a key player in regional politics, especially in tackling territorial disputes in the region, and the need to maintain the region’s status quo by appearing subservient to the members’ self-interest in protecting their national sovereignty at the expense of progress on regionalization.