Gaddafi had become accepted by the West, fulfilled all the conditions they demanded concerning weapons, had trade sanctions lifted, ruled a country in which the people were better served in education and health than most in the Middle East and North Africa. while we praised and supported regimes like Saudi Arabia and other Gulf states.

When an armed insurgency began we supported it with bombs and arms, telling our people it was for democracy.....just like we did in Iraq.
When Gaddafi's troops were incinerated and he himself brutally murdered by people who turned out to be Islamic Jihadists and brigands we washed our hands and walked away.
Mrs Clinton was seen by millions making a joke of Gaddafi's killing in a TV programme, after being the prime mover in US involvement.

According to you this was "justice" for his years of cruelty.....well if the US or the UK were faced by a serious armed insurgency financed and armed by Russia or China....we would be forced to be just as cruel.

To defeat ISIS we will have to be much more cruel than Gaddafi, Saddam, and Assad put together.