International trade has been part of the economy since ancient times. The means of trading improve along with technology, and along with them evolves the international trading.
In the past, countries could close themselves in an autarkic market, existing within a self-sufficient economy that does not rely on trade with other countries. Today, however, this is not possible. There is not a country in the world that does not export or import goods and services. In fact, there is not a country in the world that can provide for all the needs of its citizens on its own ignoring the international system.
According to data from the World Trade Organization (WTO), since WWII, the scope of international trade has risen sharply. The United States was the leader in international merchandise trade in 2010, with a trade volume of 3.25 trillion dollars (1.97 of which is imports); China was second, with approximately 2.97 trillion dollars in volume (with 183 billion dollars in merchandise trade surplus), and Germany was third with 2.34 trillion in merchandise trade volume (with a surplus of 202 billion dollars) [3].
The enormous scope of international trade exemplifies the connections and dependence among the countries, both in the real economy [4] and in finance.