In the last two decades, Thai contemporary art has secured a small but conspicuous niche on the international exhibition circuit, despite the country's meagre infrastructure for art education, presentation and promotion. To advance professionally today, Thai artists must navigate between two distinct but overlapping spheres – each with its own practical, aesthetic and political constraints – one national, the other post-national. In this article Thai contemporary art is historicised within this dual framing. It is argued that its current state of intellectual exhaustion is inextricable from a wider failure of the national project, all too obvious in the country's ongoing constitutional meltdown. The author locates key historical precedents in the 1930s, when an institutional modern art first emerged, in line with the imperatives of a modern bourgeois nationalism with aspirations towards international standing and recognition. There is then a survey of the relationship between modern art and the modern state since, charting their convergences and divergences. Here, Georges Bataille's theoretical distinction between the homogeneous and the heterogeneous affords a byway around conventional notions of state and non-state agency, specifying a kind of sovereignty – these days perhaps peculiar to Thailand – that is neither pre-modern, nor fit for today's globalised world.