The question of international law's role in progressive politics has become increasingly important. This is reflected in an upsurge in scholarship dealing with international law's relationship to imperial power and its progressive potential. There has also been an increase in the number of Marxist accounts of international law, with China Miéville's Between Equal Rights being particularly important. Miéville's book is very pessimistic as to the progressive potential of international law. This article contests Miéville's claims by examining his accounts of legal subjectivity, violence, and indeterminacy, and argues that international law's content is open to progressive appropriations. However, the ‘form’ of international law limits its ability to criticize systemic or structural problems, so that it has very little transformative potential. A progressive politics of international law must therefore take advantage of content without falling foul of form. The article finally enquires whether in some extraordinary situations international law might be transformative.