Thailand has been politically and culturally globalized. In the reign of King Rama V, the first political globalizing was to unite the land within the national boundary and to create a nation state like the West. Cultural globalizing focused on western concepts of rationality, modernity and development. The change of the policy on forests from being a natural resource or a “product” to “conservation” was found to stem from national development and conservationism, which were derived from new ideas in international development. The concept of nature conservation came into Thailand in the mid-20th century in the context of nationalization of Col. Sarit Thanarat. The proclamation of the Huay Kha Khaeng and Thung Yai Naresuan Wildlife Reserve as a World Natural Heritage Site in 1991 was an international instrument to preserve natural resources, while it was believed that the marginalized ethnic groups in the area, who earned a living by slash-and-burn agriculture, were destroying the forests. Under the context of nationalization and modernity, many ethnic groups in the area, including the Karen, were branded as “hill tribes” and forest encroachers, despite earning a living by their traditional means. The article indicates that neo-conservationism is closely related to modern development which completely separates humans from nature. The concept is totally opposite to the concept and values of local ethic groups like the Karen. These people believe that humans can exist side by side with nature, because, to them, nature is their home and their life. The case study reflects that the new globalized economic, political and cultural processes are the result of an attempt to define local cultural frameworks from an international perspective, making the historical process of the society even more complex.