Why doesn't China just buy the US and be done with it?

China can't buy the United States because it's simply not possible. The United States is a sovereign country, which means that it has its own government, laws, and economy. The US is not for sale, and even if it were, China wouldn't be able to afford it. The US has a GDP of over $20 trillion, while China's is around $15 trillion.

Furthermore, the US government has laws in place to prevent foreign ownership of certain critical industries and infrastructure. For example, there are restrictions on foreign ownership of airlines, defense contractors, and ports. These laws are in place to protect US national security interests.

Finally, even if China could buy the US, it's unlikely that the American people would be willing to sell their country to a foreign power. Patriotism is a strong value in the US, and most Americans would be outraged at the thought of their country being sold to China or any other foreign power.