Suppose Mexico and the United States were the only two countries in the world. There exists anexcess supply of pesos on the foreign exchange market. This suggests that:

International economics covers the effects upon economic activity from international differences in productive resources and consumer preferences and the international institutions that affect them.
International economics plays a crucial role in understanding and shaping the global economy. It helps explain the benefits and challenges of international trade, the effects of globalization on different economies, and the impact of economic policies on domestic and foreign markets.