Libya - Why?

I remain undecided as to the merits of our actions in Libya and totally unconvinced by the official reasons.
I understand the moral and humanitarian arguments. They are logical and perfectly acceptable, and I feel that no one could reasonably disagree with the need to stop fighting, whether it is two factions within a country, or a bully beating up someone in the school playground.
What I do find strange is this sudden outbreak of morals in our government and parts of the EU.

There has been plenty of other similar incidents of suppression and killing in African countries over the past few years, and these governments have merely sat on their hands and done nothing.
Zimbabwe, or  Rhodesia as I prefer to call it, has been terrorised by Mugabe and many thousands have been killed with even greater numbers dying of starvation and disease. The life expectancy there is now at an all time low. This for a country which, at the time of independence was the "bread basket" of Africa with one of the highest living standards on the continent.
Then there was Rwanda, a former Belgian colony, Angola and Congo, both former Portuguese colonies,  Algeria and the Ivory Coast, both former French colonies all of which have had civil wars with huge death tolls, not only from the war, but also as in Rhodesia, from the subsequent starvation.
None of these stirred the morals of any of the individual ex-colonial powers, the EU or the UN. So why should Libya.
Now there are good reasons for the EU to intervene in Libya apart from oil, the main one being the likelihood of huge numbers of refugees. Italy and Malta are already experiencing a huge influx of refugees from Tunisia, a small country compared with Libya, and were this to be repeated by similar numbers from Libya the EU could be inundated.

So, on balance, I support the action being taken at present, albeit with numerous reservations.
What I do hope is that part of the eventual resolution of the situation will involve the splitting if Libya up into the two original countries from which it was formed after the war, Cirenaica and Tripolitania which were based on the original tribal territories.