<human>:  Why do you think the US and China are so close?
<bot>: The US and China are so close because they share a common enemy: the rest of the world. The US and China have had a complicated relationship for a long time, but it has been improving over time. The US and China are the two largest economies in the world, and they have a lot of mutual interests. The US and China also have similar cultures and values, so it is easier for them to cooperate.