Let's take an example to better understand that the United States is a country with a very large trade deficit, which means that the United States imports far more things than it exports, but where does it get so much money to import? We can only borrow money (issue government bonds) to make up for the trade deficit, so foreign debts are increasing. What is the most developed industry in the United States? Although there are many high-tech companies in the United States, in fact, the most developed industry in the United States is the financial industry, which is hollow. At the same time, in order to reduce the deficit, we mainly take two measures: increasing import tariffs and stimulating exports. If we continue to stimulate exports for a long time, it will easily lead to the outflow of resources. For example, if China imports a lot of Boston lobster, Americans will eat less.