Their exchange was published in New Left Review, beginning with Poulantzas's review of Miliband's 1969 work on bourgeois democracies, The State in Capitalist Society.
[1] The exchange is typically characterized as a debate between Miliband's instrumentalist model of the capitalist state and Poulantzas' structural position; however, Bob Jessop argues that this account is misleading.
Poulantzas disagrees with Miliband's approach, adopting a structural position.
This means that if the function of the state in a determinate social formation and the interests of the dominant class coincide, it is by reason of the system itself: the direct participation of members of the ruling class in the state apparatus is not the cause but the effect.
His point of view does not allow individuals to make decisions based on their own free will; rather, their decisions are determined solely by the structure of society: For what his exclusive stress on 'objective relations' suggests is that what the state does is in every particular and at all times wholly determined by these 'objective relations': in other words, that the structural constraints of the system are so absolutely compelling as to turn those who run the state into the merest functionaries and executants of policies imposed upon them by 'the system'.