Wow! What a major league surprise this is.
Mali troops attack rival red beret camp in Bamako | World news | guardian.co.uk
And all of us thought it was going to be a walkover

Why else would the French army be involved

And, of course, none of the western powers who are involving themselves knew of these minor internal disagreements

I do believe the whole article can be summed up in two words: Mission Creep.