Humans are emotional beings; can one still be considered human without emotions while maintaining absolute rationality? People should possess hatred, but they must also remain rational.
If A kills B, and then B's son kills A, and then A's son kills B's son... how long should this hatred continue?
In my view, once both parties that initially generated the hatred are dead, the hatred should not continue. In this example, when B's son kills A, the hatred should end. A's son should understand that B's son is in this situation because his own father killed B first.
Of course, there are exceptions. For instance, if A is absolutely just and B is deeply wicked, then the hatred should end after the first death.
But why can some hatreds persist for so many generations? I believe it is either because the person is not rational themselves or because external words make them irrational. Ultimately, we need to become rational, empathize with others, and not be influenced by external rhetoric; hatred should end here.
Between nations, there is no hatred, only interests. Only true individuals can harbor hatred; any hatred should not rise to the level of nations. B's son can hate A, and if it is a national collective action, then one can hate A's governor, or even the highest official of A's country; one can hate these individuals, but not the country of A.
Question: Some people in country A do not support the country's aggressive actions but do nothing about it. They work normally to support their families, but by doing so, they pay taxes to the country, funding the aggression. Should we hate such people? This is similar to how people in China became enemies of the revolutionary party that helped them. In my lifetime - Lao She. Then there are those who support the country's aggression but only pay taxes; should we hate these people? And some people support the country's aggressive actions and provide additional funding to the country; they have not directly killed anyone. Should we hate such people?
I believe we should distinguish based on whether they provide additional funding. Those who provide extra funding should be hated; they are accomplices to the aggression. Those who only provide taxes should not be hated. Those who support but only pay taxes are like those who have criminal intent in law but do not act on it.
We should not harbor hatred towards a particular country; this country has done bad things, but only for interests. Not only is this true for this country, but it is the same for all other countries, including our own. The difference is that they did what I did not; or they did it recently while I did it long ago, and it is already in the past; or although I did it in history, that was in the previous dynasty and has nothing to do with my current dynasty.