ghostnav,
Why has the UK got involved? Maybe, just maybe, because it's the right thing to do?
Life in your world may not be "like that" but thankfully it is to some.
No other country is attacking their own civilian population like Gadaffi is. This sends out a very strong message to any others that might be thinking of it.
In your world, when you see an old lady being mugged or raped, do you walk on by saying "it's nothing to do with me?"