In a previous book The Theory of Value, Capital and Interest, the systemic theory of value was developed for a closed economy. Now the economy is opened and the same theory is applied to international trade. Both books are intended to provide an alternative theoretical paradigm. The mainstream neoclassical theory, based on Heckscheer-Ohlin-Samuelson theorem, is shown to be logically contradictory and empirically refuted, justifying the search for a new approach.