It is time for real compromise in Libya. The principal reason to support the intervention in the first place was to protect the people of Libya. Decisive action aligned the west with popular movements sweeping the Middle East and north Africa – a goal justified by both ideals and interests. For the same reasons, stopping the fighting now is more important than an opposition victory on the current terms advocated by the National Transitional Council in Benghazi.

Some conditions remain non-negotiable. Muammar Gaddafi must step down. If he remains in Libya, it must be on terms that prevent him maintaining a power base. Fighting must stop and both sides must pull out of population centres. Everything else, though, should be on the table.

Remember how the intervention began. The only ground on which the Arab world and then the United Nations could agree on the use of force was the protection of Libyan civilians. Security Council resolution 1973, which authorised the no-fly zone and other measures, listed a long set of humanitarian concerns and justifications. On April 14 Nato and its partners said that they would continue intensive bombing until Col Gaddafi stopped threatening civilians and civilian-populated areas, verifiably withdrew all his forces to bases, and permitted humanitarian access to all Libyans who need help.