The UK's foreign affairs committee accused then Prime Minister David Cameron of lacking a coherent strategy for the air campaign waged on Libya to overthrow then leader Muammar Gaddafi in 2011.
It found that the action "was not informed by accurate intelligence" , that the threat to civilians was overstated, and that the opposition to Gaddafi contained a "significant Islamist element".
Plans for the future of Libya were also flawed and this led to the country's collapse. Cameron was held ultimately accountable for this.
Britain lacked sufficient knowledge of the tribal systems in Libya and overestimated Gaddafi's abilities, believing him to be more dangerous than he was.
The committee said the British government "failed to identify that the threat to civilians was overstated", adding that it "selectively took elements of Gaddafi's rhetoric at face value".
Additionally, the aims of the military intervention were confused and changed over time from protecting civilians to regime change.
"The possibility that militant extremist groups would attempt to benefit from the rebellion should not have been the preserve of hindsight," the committee said.
Cameron was ultimately responsible for the failures of the intervention, it concluded.