What is the relationship between countries now?

China, the United States, Japan, South Korea, North Korea, Russia, India, Iran, in fact, these countries have no real die-hard allies, and they all take their own interests as the starting point first. If it is profitable, it will unite, such as Japan, South Korea and the United States. They will use old America to resist China, North Korea and Russia, and the United States will use them to contain Russia and China. As for India, it's just a pile of rubbish for everyone to play with. Secondly, when they are threatened by the same people, they will unite. For example, in World War II, aren't the United States, China and Russia all one goal?