Realist and international society theories stress external side of state power. Marxists make exactly the opposite assumption - they argue that internal relations of states are more important. External relations are not separate at all, but are fundamentally determined by internal relations.

The state is

• an executive committee for furthering the common interests of the whole bourgeoisie 
• constituted by bodies of armed men (armies, police and prisons)

Main assumptions:

1. state power = a special form of power characterised by force
2. core institutions of the state are its coercive apparatuses
3. state power is an instrument of rule by the dominant class
4. state power arises primarily from the class contradictions inside society.
5. states' roles in external relations are generally extpressions of basic class characters.

Paradox in Marxist theories of the states: 

• capitalism = emerging worldwide mode of production, which crossed boundaries; but Marxists have generally assumed that the state was a nation-state.
• so when Marx wrote about 'the common interests of the whole bourgeoisie', if taken literally he would have been referring to the worldwide capitalist class. In fact, he was referring, and so have most of his followers, to separate national capitalist classes.