Trade is the oldest and most important economic nexus among nations. Indeed, trade along with war ha been central to the evolution of international relations.

Liberal economists conceive of societies as black boxes connected by exchange rates; as long as exchange rates are correct, what goes on inside the black box is regarded as not very important.

The core of the Marxist critique of capitalism is that although the individual capitalist is rational (as liberals assume), the capitalist system itself is irrational.

In many societies the domestic social costs of adjustment to changing patterns of comparative advantage are believed to outweigh the advantages of further trade liberalization.

Specialization makes the welfare of the society vulnerable to the market and to political forces beyond national control.

The world economy diffuses rather than concentrates wealth.

Structuralism argues that a liberal capitalist world economy tends to preserve or actually increase inequalities between developed and less developed economies.