Carr challenges idealism by questioning its claim to moral universalism and its idea of the harmony of interests.
In the context of anarchy, each state is uncertain about the intentions of others and is afraid that the possible gains resulting from cooperation may favor other states more than itself, and thus lead it to dependence on others.
The League of Nations, which the United States never joined, and from which Japan and Germany withdrew, could not prevent the outbreak of the Second World War.
Policies are not, as the idealists would have it, based on some universal norms, independent of interests of the parties involved.
Accordingly, it is useless to define actions of states by exclusive reference to power, security or national interest.
International politics cannot be studied independently of the wider historical and cultural context.