Southeast Asian states are often referred to as “nations” (for example, the Association of Southeast Asian Nations or ASEAN), thus implying that the peoples of each state form only one national group and are easily distinguished and characterized. In fact, more often than not, each population of the various states shows not only differences of nationality but also many other differences. Among these factors of differentiation, the political geographer attaches particular importance to the two factors of language and nationality. These two cultural factors are elements of the “state-idea” and can affect the cohesion and strength of a state. All the newly independent states of Southeast Asia are seeking to establish their state-ideas and, i n the analysis of each state's population, these two factors can throw much light on the cohesion, functioning, and viability of that particular state.