Although old Hollande does seem to be trying to make up for France's perhaps less than pro-active reputation in the 20th century in military affairs, doesn't it; he's taking up where Sarkozy left off. One tyrant down, so let's now go on and defeat Terrorism!
So I guess you completely missed that fact that the African Union and the United Nations had already approved military action against the northern rebels. Hell one of the rebel groups, the MNLA, have declared that they're going to join the French in fighting the other rebel groups. And as the current Mali government is not a French puppet your comparisons to South Vietnam and Afghanistan are flawed.