What do you mean, principled issues cannot be compromised, and non-principled issues can be compromised.

Because it is a matter of principle, we can't be confused, and we can make concessions on small things.

Principle is the bottom line, and the question of principle is the bottom line. Therefore, the bottom line cannot be compromised, and other non-principled or non-bottom line issues can be negotiated. This is the same from the perspective of a country, a group and an individual, and there can be no bottom line. National sovereignty issues, territorial integrity, etc. It's all the bottom line, as well as teams and individuals, such as reputation, whether it touches illegal crimes and so on. , are the bottom line, are related to the principle of the problem, can't compromise at all.

The problem of principle is that you touched his bottom line, which may be related to the mistakes you can't make, or it may be contrary to morality and ethics. These are all matters of principle, which are difficult to change.