Now, I know that many nations will every now and then be nice, in the form of financial aid, medicine, military security, etc. But is it possible for a nation to, at least most of the time, place the needs of others ahead of their own?
To give an example, Australia has been sending peacekeeping soldiers to East Timor for a while, without which the Indonesians would never have allowed them to become independent. That's nice. But then, the government is harvesting oil that is clearly within the maritime boundary of East Timor.
The specifics of the example are unimportant, but I'm sure you get the idea.
Bonuse question: can a superpower act altruistically? Some "Manifest Destiny" types will claim that the USA is an altruistic superpower, but I don'tt hink I can agree with that assessment.