I think this is the closest to "absolute moral truths". People discover these because these are not some arbitrary rules, the are actually absolute, universal laws.
People understand subconsciously, for example, than a person that does good for no reason expresses higher form of being good that a person that does good in exchange for some kind of benefit.
It doesn't mean that mutually beneficial relations are not good, the society is basically built on spoken or unspoken contracts.
But we understand that a person that does good altruistically, not expecting any benefit for it, is much more likely to be trustworthy in all situation. And a person that does good expecting benefits may (not must, just may) turn on you when they stop seeing benefits.
And I think the same goes for countries.
When we see US performing their foreign relations game but only ever putting their weight when we can later find they were expecting some kind of benefit, and almost never for countries that have nothing to offer, it becomes transparent to us that US is basically much less likely to be trustworthy than if it did its actions based on principles.
French (at least in France): "c'est dans le besoin que l'on reconnaît ses amis" (nearest well-known English saying: 'A friend in need is a friend indeed').
Here in Poland we have a saying "you get to know a real friend in bad (times)" (Prawdziwego przyjaciela poznaje się w biedzie).
When you feel the values or friendship will not stand the test you will not invest yourself in it and it becomes empty words.
Just as democratic values that are set aside when it doesn't exactly align with profit or power goals.
People will not stand for something they believe to just be empty words and that's why things like Assange case are so damaging to democracy.