Why did we bomb Libya?

NATO gave air support to the rebels engaged with the Libyan army, to help them overthrow the Libyan dictatorship and Gaddafi.

Countries in the UN suffering from terrorist attacks e.g. can ask for help if the Security Council (Britain, Russia, USA, France and China) deem it appropriate to provide assisstance. If one of the "founder five" disagrees (refuses to provide help) then help cannot be granted though.