The 2011 military intervention in Libya happened under Obama. It was led by France and UK, with US support, and wouldn't have happened if Obama had not green-lighted the operation. 10 years later the country is still in the middle of a civil war, de facto cut in two opposing camps that each control roughly half of the country.

Of course, compared to Iraq invasion it was a small scale operation, but is still generally considered Obama responsibility (although of course primarily Sarkozy and Cameron responsibility).