The Italians, the British and the US have each had a role in making Libya what it is today - a bloody mess.
First the Italians invaded during World War 1. By WWII, Mussolini sent 100,000 to concentration camps.
The British took over after WWII, but weren't a lot better.
The name Omar Mukhtar was soon being heard as nationalists rallied people to their cause - the British responded by closing their newspaper.The US put a stop to that because Libya had become important in the Cold War.
There was even greater fury when London came up with a plan in 1949 to divide its three main regions between itself, France and, incredibly, Italy, the former colonial power.
Independence and the discovery of oil made things more complicated when Qaddafi & Co. overthrew the king. Nationalizing oil production made him an enemy of Cold-War-America.
For a fairly complete timeline of Libyan history, see this link.