Like it or not, these issues DO affect us. I am not a supporter of this govenrment but Cameron is absolutely right to intervene in Libya. And to carry on in Afghanistan. And to intervene as far as possible in Syria etc. All with the caveat that we help these countries to help themselves as soon as is humanly possible. As for upsetting Russia, etc, who frankly cares? Russia and China, particularly Russia, have positioned themselves to take a world view which is at variance with that of the US and the "west", not for reasons of morality or virtue, but out of a misguided belief that by standing apart they will forge an identity and therefore power for themselves.
Russia claims not to interfere in other countries' affairs but it does just that in those countries where it is able: namely its neighbouring former Soviet client states such as Georgia. Intererence takes the form of infilitration of those countries security services, and in the case of Georgia, destablising and occupying parts of its territory in the guise of peace keeping and protecting ethnic minorities. While the US, GB and NATO may have made mistakes in foreign policy and while there are aspects of foreogn intervention which are unpredictable and questionable, like it or not we DO live in an increasingly interdependent world where unrest in one country can easily cause ripples or worse further afield. And I prefer to be on the side of those, imperfect while it may be, who are trying to help, not posture for their own sake.
Critics of these actions can't have it both ways; claim it's "nothing to do with us and can hurt us" and at the same time claim its all down to "self-interest". Do you think Cameron wants to spend millions on bombing Libya when he could have done a cosy deal with Gaddafi for cheap oil? Gaddafi is in such a weak position now he'd probably give the stuff away in return for staying in power. That would be the Russian way. It isn't ours.