It is actually the other way around: this keeps the US dollar artificially high, hitting on exports, and it is completely not true that these countries can only

It is actually the other way around: this keeps the US dollar artificially high, hitting on exports, and it is completely not true that these countries can only spend dollars on American products: they can spend on anything they want, the dollar is just a currency, you can use it to buy products from Russia, China or Nigeria.