1. First of all, with foreign exchange, international trade can be carried out, which can greatly promote scientific and technological progress and economic development.

2. Because most international trade is settled in US dollars, China should hold enough US dollar assets (because the interest rate of holding US dollars in American banks is too low, it should be replaced with assets that can preserve its value, such as US Treasury bonds) to cope with the withdrawal of foreign capital and the foreign investment of domestic capital.

The American army is extremely powerful, so the American debt is very safe. Libyan currency, the new debt government can choose not to recognize it after the government collapses!